Question on Cost

A project manager is estimating project costs and needs to decide whether the estimates will include only direct costs, or whether the estimates will also include indirect costs. In which of the following phases does this decision need to take place?

A. Define Scope
B. Estimate Costs
C. Plan Expenses
D. Determine Budget

I tought this kind of decision took place in plan cost management ?
anyone can explain as the choice is not there?

thanks

I think it will be Define Scope. The PMBOK 5, Page no. 202, Section 7.2.1.3 mentions that inclusion of indirect costs is an assumtion made during this process and used as and input to Estimate process.

Can you please check with the source of the question and if this is the correct answer.