Question

Even though I had planned to go skiing with my friends, I had to ________________ at the last moment because of an injury.

• A. back up
• B. back of
• C. back on
• D. back out

Hint:

“Back out” always means withdrawing from an agreement or commitment, while “back up” is used for support or reversing a vehicle.

Answer 1

The Correct Option is D

Step 1: Meaning of the sentence.
The sentence says that the speaker had already planned to go skiing but had to cancel at the last moment due to an injury.

Step 2: Analyze each option.
(A) \emph{back up} → means to reverse or support something. Not correct in this context.
(B) \emph{back of} → not grammatically valid here.
(C) \emph{back on} → means to rely on something. Does not fit here.
(D) \emph{back out} → means to withdraw from an agreement or plan. This perfectly matches the idea of cancelling the skiing plan.

Step 3: Final Choice.
Hence, the correct option is: \(\boxed{\text{back out}}\).