Solution

The correct answer is: Option 4) A, E Only

Key Rules of Pointer Arithmetic in C

• Rule 1: pointer ± integer → pointer Adding or subtracting an integer from a pointer moves it by that many elements (scaled by sizeof(*pointer)).
• Rule 2: pointer − pointer → integer (ptrdiff_t) Subtracting two pointers gives the number of elements between them, defined only when both pointers point into the same array (or one past its end).
• Rule 3: pointer + pointer is illegal in C; there is no meaning for “adding two addresses.”

Interpreting the statements A–E

• A. pointer + number → pointer — Legal. Matches Rule 1.
• B. pointer − number → number — Illegal as written. In C, pointer − integer produces a pointer, not a number. (If this option had said “→ pointer,” it would be legal.)
• C. pointer + pointer → pointer — Illegal. Adding two pointers is not allowed (violates Rule 3).
• D. pointer − pointer → pointer — Illegal. Subtracting pointers yields an integer count, not a pointer (violates Rule 2).
• E. pointer − pointer → number — Legal. Matches Rule 2; result type is typically ptrdiff_t.

Mini examples

int a[10];
int *p = &a[3];
int *q = &a[7];

p + 2;     /* legal: pointer to a[5] */
q - 3;     /* legal: pointer to a[4] */
q - p;     /* legal: value 4 (of type ptrdiff_t) */

p + q;     /* illegal */
p - 2.0;   /* illegal: RHS must be integer, not double */
p - q;     /* legal, but result is an integer, not a pointer */

Conclusion

Only statements that conform to C’s pointer arithmetic are A and E. Hence, the most appropriate answer is Option 4) A, E Only.