What does the modulus operator (%) return in Python?

The modulus operator (%) in Python is designed to return the remainder of a division operation between two numbers. For instance, if you perform the operation 7 % 3, the result would be 1 because when you divide 7 by 3, the quotient is 2 with a remainder of 1. This unique functionality is essential in various programming tasks, such as determining whether a number is even or odd or cycling through a series of values in a loop.

The other options focus on different arithmetic operations: returning the quotient, the sum, and the difference. However, none of these operations utilize the modulus operator; they each represent distinct mathematical functions that Python can perform using other operators (such as division for the quotient, addition for the sum, and subtraction for the difference). Thus, understanding the specific role of the modulus operator is key to programming effectively in Python.