The answer is C. The program prints:
plum

Why?
A negative position counts from the end: -1 is the last item, -2 the one before it. So -2 means item number 2 from the end.
Trace table
A trace table follows the program step by step. Here’s this one:
| position | negative position | item |
|---|---|---|
| 0 | -6 | carrot |
| 1 | -5 | apple |
| 2 | -4 | melon |
| 3 | -3 | pear |
| 4 | -2 | plum |
| 5 | -1 | banana |
The code again
basket = ["carrot", "apple", "melon", "pear", "plum", "banana"]
print(basket[-2])
Try it: change one number in the program and predict the new output before you run it.