Answer: Python Puzzler #1279

The answer is A. The program prints:

[4, 8, 12, 16]

Checked by running the program for real.

range(4, 20, 4) counts from 4 in steps of 4 and stops before 20.

print(list(range(4, 20, 4)))

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