A plant with genotype $\frac{A}{a}\frac{?}{?}\frac{a}{a}$ produces gametes in which proportions?

A$/$A : A$/$a : $\frac{a}{a}$ in a $1$:$2$:$1$ ratio

$\frac{A}{a}$:$aa$ in a $3$:$1$ ratio

A$/$A : $\frac{A}{a}$:$\frac{a}{a}$ in a $1$:$4$:$1$ ratio

$\frac{A}{a}$:$\frac{a}{a}$ in equal proportions

All a$/$a