Which encoding standard is described as using 16-bit code units to represent most major languages?

• A. ASCII
• B. UTF-8
• C. Unicode
• D. ISO-8859-1

Answer: (C)

Understanding character encoding means choosing a system that can map a vast set of symbols from many languages to a form that computers can store and transmit. Unicode provides a universal map of code points for characters from virtually all languages. To store these code points, different encoding methods exist; one of them uses 16-bit units, which is how UTF-16 represents characters. In UTF-16, most common characters fit into a single 16-bit unit, making it efficient for many languages, while a small number require two 16-bit units (surrogate pairs) to represent rare or newer symbols.

This explains why Unicode is the best fit for the description: it’s the standard that, in its UTF-16 form, uses 16-bit code units to cover a wide range of languages. In contrast, ASCII is limited to 128 characters, ISO-8859-1 covers only Western European languages with 8-bit units, and UTF-8 uses 1 to 4 bytes (8-bit units) rather than fixed 16-bit units, though it can encode all Unicode code points.