Question

The Senate hoped to learn from the Watergate tapes
what did the president knew and when he knew it.
who John Dean was and when he authorized the break-in.
who the burglars were and why they staged the break-in.
when the Watergate break-in occurred and who was involved.

Answer 1

The first option. The Senate Watergate Committee sought to determine "what the President knew and when he knew it" — i.e., whether Nixon knew of or authorized the break-in and the subsequent cover-up.