Answer:
a. A literal dollar sign .
b. Shell variable syntax.
c. End-of-line anchor for pattern matching.
Explanation:
There are three answers to this question among the given options.
When a regular expression is quoted single, the $ character can act in one of two ways. end of line anchor for pattern matching.Elsewhere it acts as a literal dollar sign.
When a double quoted regular expression is there, the $ character is treated as a shell variable syntax.