ASCII stands for the American Standard Code for Information Interchange. It is a character encoding standard developed by the American National Standards Institute (ANSI) in 1963 for electronic communication.

ASCII uses 7 bits to represent 128 characters — 33 non-printing control characters and 95 printable characters covering the English alphabet (A–Z, a–z), digits (0–9), punctuation marks and basic symbols. Extended ASCII uses 8 bits and represents 256 characters.

LAN (Local Area Network) is a networking term; RAM (Random Access Memory) is a type of primary memory; CD (Compact Disc) is an optical storage medium — none of these are character encoding standards.

Hence, the answer is ASCII.