Answer: Python Puzzler #1249

The answer is B. The program prints:

[20, 13, 9, 2]

Checked by running the program for real.

sort() puts the list in order, smallest first. reverse=True flips it, so the biggest comes first. It changes the list itself.

scores = [20, 2, 9, 13]
scores.sort(reverse=True)
print(scores)

Try it: change one number in the program and predict the new output before you run it.