$/**$ NOTE: $*$ The program doesn't do anything useful and doesn't display any output on the screen. $*$ It is just an exercise for understanding the subject of "Activation Records". $*$ It shows how C functions and their variables become activated or deactivate. $*/$ #include int foo $($int$)$; int jupiter$($int$,$ int$)$; int mercury$($int$,$ int$)$; int main$($void$)\{$ int x $=2,$ y $=4,$ z $=10$; y $=$ foo$($y$)$; y $=-4+$ jupiter$($x$,$ z$)*2$ ; $//$ Point $3$ return $0$; $\}$ int mercury$($int m$,$ int n$)\{$ int t; t $=$ m $+2*$ n; $//$ Point $1$ return t; $\}$ int jupiter$($int i$,$ int j$)\{$ int d $=$ j; d $=$ mercury$($i $\%400,$ i$)$; $//$ Point $2$ return d; $\}$ int foo$($int x$)\{$ int y $=$ x; x $=$ y $*2$; return x; $\}$