Which is NOT a power of Congress?

Congress: Select the best answer from the choices provided.
A.
Holding hearings on important issues
B.
Impeachment
C.
Oversight
D.
Vetoing bills

D. Congress does NOT have the power to veto bills. That power is reserved for the executive (I.e., President). See Article 1, Section 7 of the US Constitution.

When the President objects go a bill or resolution passed by Congress, he may exercise his veto power, stopping the passage of the bill. Of course Congress may override the veto with ⅔ vote in both the House and the Senate.