Question

What is the multiplicative identity element in the set of whole numbers?

(a) 0 (b) − 1 (c) 1 (d) None of these

Answer 1

A multiplicative identity is a number which when multiplied with any number, the number
is unchanged.
For example :1 $\text{×}$ 7 = 7, 1 $\text{×}$ 9 = 9, 1 $\text{×}$ 100 = 100 etc.
Thus, 1 is multiplicative identity in the set of whole numbers is 1.
Hence, the correct option is (c).