The passage is about a book fair in the past. So, even if the sentence does not give any clues, we know that the verb should be in simple past. The action has already been completed.
"Visiting" in option A is incorrect as it is a gerund which can be used a s a noun. We need the past participle of the verb.
"Visit" in option B is the present participle of the verb and remains in tense disagreement with the context.
"Visited" in option C is correct. It is the past participle of the verb.
"Was visited" in option D is incorrect as it would imply that the subject was visited by the book fair. This is impossible and grammatically incorrect.
Thus, option C is correct.