$($define$-$struct foo $($a b c$))$

$($define F$1($make$-$foo $123))$

$($define F$2($make$-$foo $456))$

; ; Which of the following expressions produces the value $5?$

;;

;; A$.($foo$-$a F$1)$

;; B$.($foo$-$b$)$

;; C$.($foo$-$c F$2)$

;; D$.($foo$-$b F$2)$