The two correct answers are:
-
After we return from vacation, unpack our luggage, and relax for a few hours. (This is a dependent clause; it starts with "After" which makes it dependent on something else.)
-
Just in case Jonathan forgets to mow the grass in the area on the side of the garage. (This is also a dependent clause; it starts with "Just in case" indicating it relies on another part of the sentence for complete meaning.)
The other sentences provided are independent clauses.