Answer:
The correct answer is D. π
Step-by-step explanation:
Let's recall that rational numbers are those that can be written as a ratio or fraction of two integers. Quite the opposite, irrational numbers can't be written as a ratio or fraction of two integers.
Upon saying that we have:
A. A fraction with numerator negative 15 and denominator 4 is a rational number because we can represent it: -15/4
B. A fraction with numerator negative 7 and denominator 9 is a rational number because we can represent it: -7/9
C. √4 is a rational number because we can represent it: 2 or 2/1
D. π is the most known irrational number because we can't represent it as a ratio or fraction: 3.14159265358979....and more can't be written as a ratio or fraction.
The correct answer is D. π
