$A= a_{1}a_{0}$ and $B= b_{1}b_{0}$ are two $2$–bit unsigned binary numbers. If $F(a_{1},a_{0},b_{1},b_{0})$ is a Boolean function such that $F=1$ only when $A>B,$ and $F=0$ otherwise, then $F$ can be minimized to the form __________
- $a_{1}\overline{b}_{1} + a_{1}a_{0}\overline{b}_{0}$
- $a_{1}\overline{b}_{1} + a_{1}a_{0}\overline{b}_{0} + a_{0}\overline{b}_{0}\overline{b}_{1}$
- $a_{1}a_{0}\overline{b}_{0} + a_{0}\overline{b}_{0}\overline{b}_{1}$
- $a_{1}\overline{b}_{1} + a_{1}a_{0}\overline{b}_{0} + a_{0}\overline{b}_{0}b_{1}$