The answer is C. The program prints:
5

Why?
range(1, 6, 3) starts at 1, goes up in steps of 3, and stops before 6. So the loop adds 1 + 4. The total is 5.
Trace table
A trace table follows the program step by step. Here’s this one:
| number | total after the loop body |
|---|---|
| 1 | 1 |
| 4 | 5 |
The code again
total = 0
for number in range(1, 6, 3):
total = total + number
print(total)
Try it: change one number in the program and predict the new output before you run it.