Which sentence uses punctuation correctly? a. my cousin james, tired from the long day, fell asleep on the couch. b. my cousin james tired from the long day fell asleep on the couch. c. my cousin james, tired from the long day fell asleep on the couch. d. my cousin james tired from the long day, fell asleep on the couch.

A.

"tired from the long day" is an addition to the full sentence "My cousin James fell asleep on the couch." Since it's in the middle of the sentence, it makes more sense to the reader when each part is separated to indicate the transition of thought.

(There is more technical reasons for this, but thinking about it in terms of transitioning thoughts always made more sense to me personally.)