The correct option is B usefulness
The word 'futility' refers to pointlessness or uselessness.
Option A, urgency refers to importance requiring swift action.
Option B, usefulness refers to the quality of being useful.
Option C, value refers to the regard that something is held to deserve.
Option D, importance refers to the state of being great significance or value.
Thus, according to the meaning, the word 'usefulness' is the opposite of the word 'futility'.