Make supports macros, also called variables. Some common macros have standardized names: CC is the name of the compiler CFLAGS contains compiler flags, e$.$g$.$ CFLAGS $=-$Wall$-$std$=$c$99$ LDLIBS contains libraries to be included when linking, e$.$g$.$ LDLIBS $=-$lm $($links the math library$)$ Special macros begin with a dollar sign and do not need to be surrounded by parentheses. See http:$//$www$.$cprogramming.com$/$tutorial$/$makefiles$\_$continued.html for more information. They can be used to avoid repeating target names and dependencies: $@ is the name of the target, often used after the $-$o flag. $$^$ stands for all dependencies, which is useful for linking rules. $$<$ stands for the first dependency, which is useful after the $-$c flag in compilation rules. Define the CC$,$ CFLAGS, and LDLIBS macros in your makefile with the appropriate values. Comment out the make rules that were added in section $3,$ and replace them with new rules that use these macros and the listed special macros wherever possible. This final version must be the one that runs when make lab$2$ is called from the command line.