(A) ** For no reason
(B) Disrespectfully
(C) Die
(D) To decide
EXPLANATIONS BELOW
Concept note-1: -If you say that something such as someone’s death, suffering, or effort was in vain, you mean that it was useless because it did not achieve anything.
Concept note-2: -in vain. : to no end : without success or result. her efforts were in vain. : in an irreverent or blasphemous manner.
Concept note-3: -She struggles in vain, screaming and trying to get away. Several times they tried to move it, but in vain.
Concept note-4: -’Vain’ and ‘In Vain’ Meaning and Usage It also appears in the idiom “to take someone’s name in vain, ” meaning “to use (a name, especially the name of God) in a way that does not show proper respect."
Concept note-5: -adjectivebringing no advantage, product. abortive. barren. empty. futile.