The answer is C. The program prints:
2

Why?
count goes through the string and counts how many times ‘p’ appears.
Trace table
A trace table follows the program step by step. Here’s this one:
| letter | matches? |
|---|---|
| b | |
| e | |
| e | |
| p | yes |
| (space) | |
| b | |
| o | |
| o | |
| p | yes |
The code again
word = "beep boop"
print(word.count("p"))
Try it: change one number in the program and predict the new output before you run it.