*question number 75*/
Which one of the following is true for identifiers that begin with an underscore?
They are generally treated differently by preprocessors and compilers from other identifiers.
They are case-insensitive.
They are reserved for usage by standards committees, system implementers, and compiler engineers.
Applications programmers are encouraged to employ them in their own code in order to mark certain symbols for internal usage. Choice 5
They are deprecated by Standard C and are permitted only for backward compatibility with older C libraries.
Is the answer (1) ?