Explanation:

The term CHARSET is commonly used as a synonym for character set, which refers to a collection of characters that can be used by a computer system or program. In the context of encoding, a CHARSET specifies the mapping of characters to their corresponding numeric values, such as in UTF-8 or ASCII.

• CHARSET is a widely recognized abbreviation and is used in various contexts, including HTML, HTTP headers, and databases.

Why the other options are incorrect:

• (B) CHCSET: This is not a commonly used abbreviation for character set.
• (C) CSET: Although it's a possible abbreviation, it is less standard and not widely used compared to CHARSET.
• (D) CHSET: Similarly, this is not a commonly accepted abbreviation for character set.

Thus, (A) CHARSET is the most widely recognized synonym for character set.