What can be stored in a single byte?

A single byte can hold one character because it consists of 8 bits, which provides enough combination to represent 256 different values. This range allows a single byte to encode standard ASCII characters, including uppercase and lowercase letters, numerals, and various symbols.

In terms of other options, a whole word typically requires multiple bytes, as words can vary in length and often exceed 8 bits. Similarly, a number can be represented by a single byte, but this option does not cover the breadth of what a byte can store (i.e., characters). Lastly, a sentence far exceeds the capacity of a single byte as it contains multiple characters and would require many bytes to represent. Thus, the most accurate representation of what can be stored in a single byte is indeed a single character.