This question is from Pmzilla tough question ( Admin  I hope you dont mind that I post it here )

q15

While controlling procurements, you have found that contractor used iron pipes to do the project work, while the contract clearly states that copper pipes are to be used. The contract work is almost nearing completion and ther eis no way for you to recover this loss and has put your project in jeopardy. what will you do ?

A ) Ask the contractor for explanation and give a new estimates and completion dates

B ) File a material breach against the contractor

c ) Use integrated change control process to submit a change request for using iron pipes instead of coppers pipes

d) Contractor has breached contract terms and you should check with contract administrator on retainage clauses.

Answer is B

I was wondering why D is wrong, to me D sounds like B but better?