Question

$1$ is the multiplicative identity for ........

• A. whole numbers
• B. integers
• C. rational numbers
• D. all of the above

Answer 1

The correct option is D all of the above

We know that whole numbers are a subset of integers which in turn are a subset of rational numbers. Also, $1$ is the multiplicative identity for rational numbers because the product of $1$ and any rational number is the rational number itself.

Thus, $1$ is the multiplicative identity for whole numbers, integers and rational numbers.