You are the project manager for a project. While reviewing the cost estimates for the project you notice that one of the cost estimates for an?

(C)

to ask the responsible person of the estimate if he has logical reason for the raise

If i am the project manager then i will follow below steps :

1. Ask the person responsible about the difference

2.Get Estimate ,  Reduce the estimate

3. Accept the estimate

It is more convenient answer Option C -  Ask the Person Responsible about the Difference.

Thank you for invitation. I think C. Developing project schedule with contingency reserves as a recognition of the schedule risk.

C. Ask the person responsible about the difference

Option - C is most appropriate action to be taken under the circumstances.

you should analysis and as the responsible emp. 

Indeed C.: Ask the person responsible about the difference and try to analyse why it happened