The code which uses 7 bits to represent a character is

CONCEPT — A fixed-width binary code with n bits can represent 2n distinct patterns. A character encoding assigns those patterns to control characters, letters, digits, and symbols.

APPLICATION — Original ASCII defines 128 code points numbered 0 through 127. Since 128 = 27, each original ASCII code point is represented by a 7-bit binary value.

CONTRAST

• BCD represents each decimal digit separately as a four-bit binary value.

• EBCDIC is an IBM character encoding organized around byte-sized code values.

• Gray code is a reflected binary ordering designed so adjacent values differ in one bit; it is not a character set.

RESULT — The code described is ASCII.