Oxford, Cambridge and RSA (OCR) GCSE Computer Science Practice Exam

The term that refers to a single alphanumeric symbol in programming is "Character." In programming, a character is defined as any single letter, numeral, symbol, or whitespace that can be represented in the code. For instance, in the ASCII character set, characters include uppercase and lowercase letters (like A, b), digits (like 1, 2), punctuation marks (like !, ?), and special symbols (like #, @).

Other terms, while related, do not specifically describe a single alphanumeric symbol. A string refers to a sequence of characters, which means it can contain multiple alphanumeric symbols or any combination of characters. A literal is a fixed value in the code, such as a specific number or a string represented in quotes, which again requires more than just a single character. An identifier, on the other hand, is a name used to identify a variable, function, or other entities in the code, and is made up of one or more characters but does not represent a single symbol. Thus, "Character" is the most accurate term for a single alphanumeric symbol in programming.