$[4$ Points$]$ Answer the four questions using the graphs below $(($c$)(\backslash (\backslash$epsilon $\backslash )($b$)($d$)($f i$.$ Which of the graphs above is only concave up and increasing? Choose only one. $($a$)))$ ii$.$ Which of the graphs above is only concave down and increasing? Choose only one. $($a$))($c$)($d$)($e$)($f$)$ iii. Which of the graphs above is only concave up and decreasing? Choose only one. $($a$)$ a $($b$)($c$)($d$)($e$)\backslash (\backslash$square$(\backslash$mathrm$\{$f$\})\backslash )$ iv$.$ Which of the graphs above is only concave down and decreasing? Choose only one. $($a$)($b$)($c$)($d$)($e$)\backslash (\backslash$square $\backslash )($f$)$