A.string.h B.stdlib.h C.ctype.h D.math.h
A.printf("x/y=%d\n",(x+3)/(y-3)); B.printf("x/y=%d\n",x+3/y-3); C.printf("div(x,y)=%d\n",x+3/y-3;); D.printf("x/y=%d\n",x+3/y-3;);
A.#definepi=3.14159; B.definepi=3.14159 C.#definepi="3.14159" D.#definepi(3.14159)