The number that fits into all the following number sets: natural number, whole number, and integer is 8.
- Natural numbers are positive integers (1, 2, 3, ...).
- Whole numbers are non-negative integers (0, 1, 2, ...).
- Integers include all whole numbers and their negative counterparts (-2, -1, 0, 1, 2, ...).
Among the options provided, 8 is the only number that is a natural number, a whole number, and an integer.