Which of these numbers is classified as a rational number?

Yes.

To determine which of these numbers is classified as a rational number, we need to understand what a rational number is. A rational number is a number that can be expressed as the quotient or fraction of two integers, where the denominator is not zero.

A. Square root 17: The square root of 17 is an irrational number because it cannot be expressed as a fraction of two integers. It is not the answer.

B. Square root 23: The square root of 23 is also an irrational number because it cannot be expressed as a fraction of two integers. It is not the answer.

C. Square root 9: The square root of 9 is equal to 3, which is a whole number. Any whole number can be expressed as a fraction with a denominator of 1. Therefore, the square root of 9 is a rational number.

D. Square root 2: The square root of 2 is an irrational number because it cannot be expressed as a fraction of two integers. It is not the answer.

Based on this, the answer is indeed C. The square root of 9 is classified as a rational number.