Correct Answer: assent

Solution : The correct choice is the first option.

Explanation:

Assent means to agree or express approval.

Ease means to make something less difficult or more manageable; the opposite of difficulty or hardship.

Restore means to bring back or return something to its original state; the opposite of damage or loss.

Ascertain means to find out or make sure of something; the opposite of uncertainty or doubt.

In the context of the sentence choosing assent as the antonym makes sense, as object in this context means expressing disagreement or disapproval.