Respuesta :

Answer:

A. declared

Explanation:

Before a structure can be used, it must be  declared.

For example:

// Structure definition

struct s{

int a;

char b;

};

// Structure instantiation

struct s  mystruct;

// This is where a structure instance called mystruct is created whose

// datatype is struct s.

mystruct.a = 10;

mystruct.b = 'c';

As we can see from the example definition precedes use for the structure.