Answer:
D.
Step-by-step explanation:
The definition of a rational number is a number that can be expressed as the ratio of two integers.
We cannot represent pi as a ratio of two integers, so it cannot be A. Apply the same definition and B and C are out.
We know that 0.333... = 1/3. This number can be represented as the ratio of two integers, so this is the correct answer.
I hope this helps!
