Is this sum rational or irrational? Explain.

1. 12 + 18/7 (1 point)

The sum is rational because both 1. 12 and 18 are rational, and the sum of rational numbers is rational.

The sum is irrational because 1. 12 is irrational, and the sum of a rational number and an irrational number is irrational.

The sum is rational because both 1. 12 and 18 are positive, and the sum of positive numbers is rational.

The sum is irrational because 18 is irrational, and the sum of a rational number and an irrational number is irrational. ​