Below, a word is given followed by three sentences which consist of that word. Identify the sentence/s which best expresses the meaning of the word. Choose option 5 (None of these) if the word is not suitable in any of these sentences.
Futile
A. Despite their best efforts, all attempts to solve the problem proved futile .
B. She enjoyed the futile effort of organizing the event for weeks.
C. Their futile arguments never led to any meaningful conclusions.