Final answer:
The word perturb most closely means to annoy, as it implies causing disturbance or unease to someone.
Step-by-step explanation:
The word perturb is most similar in meaning to the word annoy. When you perturb someone, you disturb or make them uneasy, which is a sensation closely related to annoyance. This is distinctly different from assisting, destroying, or reducing something. Therefore, the correct answer is c. annoy.
The word 'perturb' means to make someone anxious, unsettled, or annoyed. Among the given options, the word that is most similar in meaning to 'perturb' is annoy.