Answer:
The correct answer is "are visiting"
Step-by-step explanation:
The verb "visit" is a regular verb, therefore the conjugation to present participle involves only the addition of "ing" at the end of the word, which results in the word "visiting". Since the example states the action of the noun "They" the correct form of the verb is "are visiting". The full sentence is "They are visiting the office next month to take inventory".