It was a facetious remark which totally failed to make any impression.

Answer: Option B

Irrelevant : not connected with or relevant to something.
Joking : humorous or flippant.
Reconciliatory : intended or likely to restore friendly relations.
Meaningless : having no meaning or significance.
Facetious : treating serious issues with deliberately inappropriate humour; flippant.

Synonym of Facetious is Joking