Answer: Python Puzzler #1227

The answer is D. The program prints:

[1, 4, 7, 10, 13, 16]
What the program prints
Checked by running the program for real.

Why?

range(1, 19, 3) counts from 1 in steps of 3 and stops before 19.

The code again

print(list(range(1, 19, 3)))

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