Final answer:
Numbers -1 and 0 are examples of integers that are not natural numbers because natural numbers start from 1, and these are non-positive.
Step-by-step explanation:
When determining if a number is an integer but not a natural number, it is essential to remember the definitions of integers and natural numbers. The set of integers includes all whole numbers and their negatives, i.e., ..., -3, -2, -1, 0, 1, 2, 3, ...
By contrast, natural numbers are a subset of integers and include all positive integers starting from 1, i.e., 1, 2, 3, ... Thus, option d) -1 and 0 are integers but not natural numbers because they are non-positive. Option -1 is a negative number and 0 is neither negative nor positive, but natural numbers start at 1.