Answer: Python Puzzler #1743

The answer is C. The program prints:

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

Why?

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

Trace table

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

keyvalue
lionroar
duckquack
cowmoo
owlhoot

The code again

sounds = {
    "lion": "roar",
    "duck": "quack",
    "cow": "moo",
    "owl": "hoot",
}
print(sounds["lion"])

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