Which statement is true about the relationships between the number sets?
A. All integers are also rational numbers
B. Whole numbers include all positive integers and negative integers
C. Some irrational numbers are also integers
D. Not all natural numbers are real numbers
The correct answer is D. Not all natural numbers are real numbers.
The natural numbers include all positive whole numbers (1, 2, 3, 4, ...). However, the set of real numbers includes not only all natural numbers but also all rational and irrational numbers. Therefore, not all natural numbers are real numbers.