You are working with XYZ organization. Your senior manager imposed new delivery date which is earlier than mentioned project deliverable date in scope statement. To whom you are most accountable?

C accountable to the project sponsor 

In my opinion -  A. customer --

Thank you for invitation. My answer is Option -C sponsor.

To whom you are most accountable ? - If this question is right , I will choose option B - team member/s out of the given options and in the given situation. 

My answer is for option (C)