Answer:
The correct verb that completes the sentence is:
A) Visitando.
Step-by-step explanation:
The word "visitando" is the one that gives more meaning to the sentence, it is used when you say that a person is exploring places and looking at the culture, the continuous verb is used (because the action is happening at that moment) "visit "conjugating it with the pronoun in the sentence.
So, the sentence in Spanish is:
Sophie y Charlie están visitando muchos lugares en Honduras y El Salvador.