Answer:
As an affirmation of her loyalty, Keysha agreed to become a secret agent.
Explanation:
A noun is defined as a word that can function both as the subject or the object in a sentence, it is used to name people, places, animals, things, qualities and states.
There are two clauses in each option. In letter A, the first one contains the subject pronoun she which could be changed for Keysha in the second clause.
In the second one, the noun could be agent in reference to Keysha.
In letter C, it is not possible to find a substitution for affirmation or loyalty in the second clause.
In the last option, the word that can be changed for a noun is she, using Keysha to replace it.
