Which example is NOT an irrational number?

3/4 is a rational number because it can be expressed as a fraction where both the numerator (3) and the denominator (4) are integers, and the denominator is not zero. Rational numbers are defined as numbers that can be written as the quotient of two integers. In contrast, irrational numbers, such as π, √2, and e, cannot be represented as a simple fraction; they have non-repeating, non-terminating decimal expansions. Thus, the example of 3/4 stands out as the only choice that meets the criteria for being a rational number.