What defines the hexadecimal number system?

The hexadecimal number system is defined as a base-16 system that uses the digits 0 through 9 and the letters A through F. This means that it comprises 16 unique symbols in total, where the numbers 0 to 9 represent their usual values, and the letters A, B, C, D, E, and F correspond to the decimal values 10 through 15, respectively.

This base-16 system is widely used in computing and digital electronics because it can represent large binary numbers more compactly and clearly. For instance, a single hexadecimal digit can express four binary digits (bits), making it easier for programmers and engineers to work with binary-coded values.

The other answer choices refer to different bases: a base-8 system (octal), a base-10 system (decimal), and a base-2 system (binary), none of which accurately describe the hexadecimal system. Thus, the defining characteristics of the hexadecimal number system are encapsulated perfectly in the third option, confirming its status as a base-16 system.