6347. Some of the members of the Board indulged in highly scurrilous talk at the meeting.

✅ The correct answer is option C.
Irrelevant : not connected with or relevant to something.

Superfluous : unnecessary, especially through being more than enough.

Abusive : extremely offensive and insulting.

Objectionable : arousing distaste or opposition; unpleasant or offensive.

Scurrilous : making or spreading scandalous claims about someone with the intention of damaging their reputation.

Synonym of Scurrilous is Abusive