He had the nerve to suggest that I was cheating.

Answer: Option B

Courage : the ability to do something that frightens one; bravery.
Audacity : rude or disrespectful behaviour; impudence.
Capacity : the maximum amount that something can contain.
Strength : the quality or state of being physically strong.
Nerve : impudence or audacity.

Synonym of Nerve is Audacity