Final answer:
B. 3, 7. The set of outcomes in which you win the game by choosing Cube B, labeled with 3 and 7, is {3, 7}.
Step-by-step explanation:
To determine the set of outcomes in which you win the game, we need to consider the possible outcomes when you choose Cube B. Cube B has faces labeled 3 and 7, so the set of outcomes in which you win the game would be the outcomes that result in either a 3 or a 7 being rolled.
The set of outcomes in which you win the game is B. 3, 7.