Choose the word closest to opposite in meaning to the italicized word-
The heroine's infidelity finds no mention in this biography.
a) Loyalty
b) Innocence
c) Intelligence
d) Charity

Hint: The dictionary meaning of the word ‘infidelity' is ‘the action or state of being unfaithful to a spouse or other sexual partner.

Complete answer:
‘Infidelity' is a noun which means (an act of) having sex with someone who is not your partner/husband. For example, Her infidelity continued even after his marriage. Here, we have to find out the antonym (closest to the opposite in meaning) of the word ‘infidelity'.
Now, let us examine all the given options to find out the correct answer :
Option ‘a’ is Loyalty. It is a state or quality of being loyal; faithfulness to commitments and obligations. For example, People give examples of her loyalty.
Option ‘b’ is Innocence. It is a noun that means a state or quality of being innocent of a crime or offense. For example, They will have to prove their innocence.
Option ‘c’ is Intelligence. It is a noun that means the ability to acquire or apply knowledge and skills. For example, He uses his intelligence at the right time.
Option ‘d’ is Charity. It is a noun that means an organization set up to provide help and raise money for those in need.
As we have analyzed all the given options, we can easily figure out the correct option. Here, the antonym (closest to the opposite in meaning) to the word ‘infidelity’ is ‘loyalty’. Hence, the option ‘a’ is the correct option.

Note:
 All the other options are plausible distractions. Don’t confuse between ‘innocence' and ‘loyalty'. They both have different meanings and different usage.