Answer: Python Puzzler #3778

The answer is C. The program prints:

squeak

This answer was checked by running the program for real.

Why?

A dictionary stores pairs: a key and its value. sounds["mouse"] looks up the key ‘mouse’ and gives back its value.

Trace table

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

key	value
cow	moo
mouse	squeak
cat	meow
frog	ribbit

The code again

sounds = {
    "cow": "moo",
    "mouse": "squeak",
    "cat": "meow",
    "frog": "ribbit",
}
print(sounds["mouse"])