What happens when you call a generator function?

The correct answer is Option C: It sets up a generator object.
When you call a generator function in Python, it doesn't immediately produce all values or return a list of values. Instead, it sets up and returns a generator object. This generator object can then be used to iterate over the values produced by the generator function. The generator object maintains the state of the generator function, allowing it to yield values lazily, one at a time, as needed. This lazy evaluation mechanism enables efficient handling of large datasets or infinite sequences without loading all values into memory at once.