The true statement about the relationships between the number sets is:
Whole numbers include all natural numbers and 0.
Here's a brief explanation of the other statements:
- All rational numbers are also integers. (False: Rational numbers include fractions, while integers are whole numbers without fractional parts.)
- Not all natural numbers are real numbers. (False: All natural numbers are indeed real numbers.)
- Some irrational numbers are also integers. (False: By definition, irrational numbers cannot be expressed as a fraction of two integers, so none can be integers.)
Thus, the correct option is about whole numbers.