In C

Question 1 1 pts Consider the following 3 code fragments 1) int *ptr = malloc ( sizeof (int)*3); ptr[0] = 0; ptr[1] 0; ptr[2] = 0; 2) int *ptrcalloc(1, sizeof (int)); if (ptr NULL) printf("Unable to allocate memory. "); exit(1) realloc(ptr, 3*sizeof (int)) if (ptrNULL) printf("Unable to allocate memory. "); exit(i) ptr[0]=0; ptr [ 1 ] = 0; ptr[2] 0; 3) int *ptr = calloc ( 3 , if (ptr == NULL ){ sizeof ( int ) ) ; printf("Unable to allocate memory. "); exit(1) Dynamically allocating an integer array of size 3 and initializing all its elements to O is safely done in code fragment(s) O 1 only O 1, 2 and 3 O 2 and 3 O 1 and 3 O 3 only