Answer:
The correct answer is 12.
Explanation:
There are four reindeer, Prancer, Quentin, Rudy, and Jebediah.
They are supposed to be put in a single file line to pull the sleigh.
However, Rudy and Prancer are best friends and need to be together, or they won't fly.
Thus the number of ways the reindeer are arranged are 3! × 2! = 6 × 2 = 12.
Therefore the reindeer can be arranged in 12 different ways to pull the sleigh.