The true statement among the options provided is:
C. every integer is a rational number.
Explanation:
- A. Every real number is an integer: This is false because real numbers include rational and irrational numbers, whereas integers are a specific subset of real numbers.
- B. Every integer is a counting number: This is false because integers include negative numbers (e.g., -1, -2) which are not counting numbers (counting numbers start from 1 and include only positive whole numbers).
- C. Every integer is a rational number: This is true because any integer can be expressed as a fraction (e.g., \( n = \frac{n}{1} \)), which fits the definition of rational numbers.
- D. Every terminating decimal number is an irrational number: This is false because terminating decimal numbers (like 0.5 or 1.25) are rational numbers, not irrational.
Thus, the correct option is C.