The answer is D. Because 'though', 'whereas' and 'while do not fit if you say it out loud
Answer: The right answer is the D) Abdul and Eliza looked forward to their vacation, but they returned home early because it rained the entire time.
Explanation: Just to elaborate a little on the answer, it can be added that the conjunction because has been correctly used here in order to explain the reason why Abdul and Eliza returned home early, even though they looked forward to their vacation—they returned because it rained the entire time. The conjunctions though, whereas, and while, however, have been incorrectly used, since they suggest contradictory and illogical ideas. For instance, if it rained the entire time, they probably had reason not to be enjoying their vacation, so saying that they returned home although it rained does not make sense.
