$1.$ Is AG a candidate key?

$2.$ Is AG a superkey? Does AG $->$ R$?==$Is $($AG$)^+$ subset of R

$3.$ Is any subject of AG a superkey?

$4.$ Does A $->$ R$?==$Is $($A$)^+$ subset of R

$5.$ Does G $->$R$?==$ Is $($G$)^+$ subset of R