Answer: Python Puzzler #3949

The answer is B. The program prints:

33

This answer was checked by running the program for real.

Why?

The loop remembers the biggest number it has seen so far, and replaces it whenever it finds a bigger one. This is how computers find the maximum.

Trace table

A trace table follows the program step by step. Here’s this one:

n	n > biggest?	biggest
4	yes	4
33	yes	33
28	no	33
27	no	33
13	no	33

The code again

numbers = [4, 33, 28, 27, 13]
biggest = 0
for n in numbers:
    if n > biggest:
        biggest = n
print(biggest)