Translate the following English sentence into the language of propositional logic. $$Something is a chair if and only if you can sit on it and it has four legs.$$ c $=$ is a chair; s $=$ sit on it; f $=$ four legs

$($A$)$ c $->($s & f$)$

$($B$)$ c $($s & f$)$

$($C$)$ c $($s & f$)$

$($D$)($s & f$)->$ c