Final answer:
The mathematical term that best illustrates rational numbers is Real.
Step-by-step explanation:
The mathematical term that best illustrates rational numbers is Real. Rational numbers are any numbers that can be expressed as a fraction, where both the numerator and denominator are integers. Examples of rational numbers include 2/3, -5/4, and 0.25. Real numbers include rational numbers, as well as irrational numbers, such as √2 and π. Therefore, the correct answer is option b) Real.