What is True in C programming A multiple fn definitions and multiple declarations B 1 declaration multiple fn definitions C 1 fn definition 1 declaration D multiple declaration 1 definition?

Answer 1

A function's declaration must be visible within every translation unit that uses that function, thus multiple declarations are permitted. To ensure consistency across all translation units that use a function, the declaration is usually placed in a header which can be included wherever it is needed. Formal arguments need not be named in a declaration (they do not form part of the function's prototype), but named arguments can provide better documentation and need not match the names used by the definition, or indeed by any other declaration of the same function.

Note that a definition is itself a declaration, thus if a function is declared (but not yet defined), there has to be at least two declarations because the function must be defined somewhere.

The "one definition rule" (ODR) implies there can only ever be one definition of a function, however multiple definitions are permitted provided those definitions appear in different translation units and are token-for-token identical (including the names of formal arguments). Being token-for-token identical means there is only one definition.

Thus the correct answer is D: multiple declarations with one definition.