Why is the inverse QFT used in QPE?

Why is the inverse Quantum Fourier Transform applied in Quantum Phase Estimation?

A

To spread the measured bitstring evenly across all outcomes so that no phase is favoured

B

To convert phase information encoded in amplitudes into a measurable computational-basis bitstring

C

To convert the input eigenstate into an equal superposition before the controlled unitaries run

D

To undo the controlled unitary operations so the register returns to its starting state