Answer: Python Puzzler #1488

The answer is B. The program prints:

ribbit

Checked by running the program for real.

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

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

sounds = {
    "duck": "quack",
    "frog": "ribbit",
    "cat": "meow",
    "lion": "roar",
}
print(sounds["frog"])

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