Answer: Python Puzzler #1871

The answer is C. The program prints:

tobor
What the program prints
Checked by running the program for real.

Why?

[::-1] is a slice that steps backwards through the string, so it reverses it.

The code again

word = "robot"
print(word[::-1])

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