Two of the following statements are true, and one is false. Identify the false statement:

a$.$ In C#$,$ an identifier must begin with an underscore, the at sign $($ @ $),$ or an uppercase letter.

b$.$ An identifier can contain only letters, digits, underscores, and the @ sign, not special characters such as #$,$ $$,$ or &$.$

c$.$ An identifier cannot be a C# reserved keyword.