1. The problem asks which of the given numbers is a natural number. 2. Natural numbers are positive integers starting from 1, 2, 3, and so on. 3. Let's analyze each option: - $\frac{220}{708}$: This is a fraction. Simplify it: $$\frac{220}{708} = \frac{\cancel{220}}{\cancel{708}} = \frac{110}{354} = \frac{55}{177}$$ Since it is not an integer, it is not a natural number. - $\sqrt{73}$: 73 is not a perfect square, so $\sqrt{73}$ is irrational and not a natural number. - $\sqrt{49}$: 49 is a perfect square, $\sqrt{49} = 7$, which is a natural number. - $-\sqrt{49}$: This equals $-7$, which is negative and thus not a natural number. 4. Therefore, the only natural number among the options is $\sqrt{49} = 7$. Final answer: $7$