OK, if the customer refered here is the buyer(or client), then within the choices, whats wrong if i select for instance the project initiator? If the SOW are contained in the RFP, who then prepares the RFP? is it not the project initiator or the PM?

If you will go back to the PMBOK, i will copy and paste it below:

Section 4.1.1.1

The statement of work (SOW) is a narrative description of products or services to be delivered by
the project. For internal projects, the project initiator or sponsor provides the statement of work based
on business needs, product, or service requirements. For external projects, the statement of work can
be received from the customer as part of a bid document, for example, request for proposal, request
for information, request for bid, or as part of a contract.

Look dude, and analyze. For internal projects, the project initiator or sponsor provides the SOW. Now my question to you is, what is the difference between the "external" project why PMBOK did NOT USE the same terms - "project initiator" or project sponsor" if the word customer here refers to the same (buyer/client or sponsor or initiator as you pointed out in your rebut?  :-)

Do you think of it as a lapses of the authors of PMBOK and its technical reviewers?

Now, with this premise, CAN WE SAY THAT REGARDLESS WHETHER THE PROJECT IS INTERNAL OR EXTERNAL, THE SOW IS ALWAYS PREPARED BY THE SPONSOR (WHO IS THE SAME AS THE BUYER, CLIENT OR CUSTOMER)???  

Moreover, it is not a matter of ego sspawar, may be it is ur own feeling but miine is not. See your first post to which i reacted. Your statement there was "When project is external , It could be received by buyer/customer in the form of RFP, RFQ, Bid proposal or as a contract" NOTE dude that RECEIVED BY IS TOTALLY DIFFERENT from RECEIVED FROM. That is what i was trying to emphasize in my earlier post.

To all of you guys, I am doing these kind of analysis and reactions not to boast myself, BUT for us to become also much aware and learn from it, i know most of you agree with me in this context, not for just the sake of debate or whatever, but IN ORDER TO LEAVE A VERY CLEAR PICTURE OF THE QUESTION, HOW QUESTION MUST BE UNDERSTOOD AND INTERPRETED IN ORDER TO GET THE VERY BEST ANSWER WITH A DEEP UNDERSTANDING OF THE ISSUE, and ABOVE ALL, LEARN some techniques in dealing with PMP questions and how wisdom, actual experience, and as well as the "English" language would mean - our english skills is inevitable here as this is the medium language for the PMP exam may contribute in your successful preparation for the PMP exam and also for your actual Project Management exercise.

My colleague “projmanpro” has explained very nicely about it. The problem is these:
1. You read and copy paste, but you do not understand what are you coping-pasting.
2. Your company may follow different processes, even PMI says project management is not a fix and firm process; it differs from company to company. But this does not mean that I start saying what my company does is a universal law. I would always go by PM body of knowledge.
3. As you see, all tricky and good questions are solved by making use of common sense and using PM knowledge you have acquired. If you keep doing keyword search and be happy that you have found out diamond, please remain happy, I cannot stop you, but in reality your happiness is for the charcoal (coal) you have found out and not diamond. If you keep aside common sense and stick to book keywords without understanding it, all I can say is…All the best!
4. If I say, I love to walk, it does not mean I cannot run. Such basic things a good author (research thesis) does not mention, its expected that the reader reads and understand the same way.

Thanks for inventing a new term “egostorming”, you can think out of box for sure, but please apply same super mind to think about the question and its relevance.