Final answer:
The set that includes the number -17 is option B) {-20, -15, -10, -5}.
Step-by-step explanation:
The correct set that includes the number -17 is option B) {-20, -15, -10, -5}.
To determine if -17 is in the set, we simply check if it is one of the elements listed. In option B, -17 is present, so that set includes the number -17.