Consider the declaration below:
typedef char *Str_typed;
#define Str_defined char*
Str_typed s1, s2;
Str_defined s3, s4;
Which one of the following statements is correct?
I. $s1$, $s2$, $s3$ and $s4$ are character pointers
II. $s1$, $s2$, $s3$ and $s4$ are characters
III. $s1$, $s2$, $s3$ are character pointers while $s4$ is a character
IV. None of the above