Which of the following rational numbers is equal to its reciprocal?

Concept use:

The rational number that is equal to its reciprocal should satisfy the equation n = 1/n, where n is the rational number.

Calculations:

Checking each option:

If n = 1, its reciprocal is also 1 (since 1/1 = 1), so that matches.

If n = 1/2, its reciprocal is 2 (since 1/(1/2) = 2), which does not match.

If n = 2, its reciprocal is 1/2 (since 1/2 = 0.5), which does not match.

For n = 0, the reciprocal is undefined (since 1/0 is undefined), which does not match.

So, the  Correct answer is Option 1.