Solution

(a) char endOfCharArray, int argc, char** argv, int ret, int i. (b) char** argv, char* argv[$i$ ] for all $i\in\{0,\ldots,$argc$-1\}$ . (c) Five pointers: argv and argv[$i$ ] with $0\le i\le 3$ . (d) The output is:

./variables_pointers
123
456
789