Question

which word/phrase best completes the sentence? in fact, besides, as a result im too tired to go for a walk ____, it looks like its going to rain.

Explanation:

We need to choose a phrase that adds another reason for not going for a walk (being too tired is one, and the rain is another). "Besides" is used to add additional information or reasons, which fits here. "In fact" is for emphasizing or clarifying, and "As a result" is for showing a consequence, neither of which fit the context of adding a reason.

Answer:

Besides