The correct answer is D. Control unit.
The control unit is the part of a computer that interprets program instructions and initiates control operations. It is responsible for fetching instructions from memory, decoding them, and then executing them. The control unit also controls the flow of data between the different parts of the computer.
The input unit is responsible for accepting data from the user or from another computer. The storage unit is responsible for storing data and programs. The logic unit is responsible for performing arithmetic and logical operations.
None of the other options are correct because they are not responsible for interpreting program instructions and initiating control operations.