The answer is A. The program prints:
[43, 28, 23, 22, 19, 10]

Why?
sort() puts the list in order, smallest first. reverse=True flips it, so the biggest comes first. It changes the list itself.
The code again
scores = [43, 22, 28, 10, 23, 19]
scores.sort(reverse=True)
print(scores)
Try it: change one number in the program and predict the new output before you run it.