The true statement about the relationships between the number sets is:
D. Whole numbers include all natural numbers and 0.
Here's a brief explanation of why the other statements are false:
A. All irrational numbers are also integers. (False - Irrational numbers cannot be expressed as fractions and are not integers.)
B. Every number is a whole number. (False - There are various types of numbers, including fractions, irrational numbers, and negative numbers that are not whole numbers.)
C. Only positive numbers make up the set of integers. (False - The set of integers includes negative numbers, zero, and positive numbers.)
So, only statement D is correct.