The set of numbers that is always rational is:
B. integers
Integers are whole numbers that can be positive, negative, or zero, and they can be expressed as a fraction of two integers (for example, \(5 = \frac{5}{1}\)). All integers are rational numbers, but not all decimals or positive/negative numbers are necessarily rational. For instance, some decimals are irrational (like \(\pi\) or \(\sqrt{2}\)), and positive or negative numbers could also be irrational.