Question $2)$ Fig. $2$ contains a pass$-$gate logic network

a$.)$ Determine the truth table for the circuit. What logic function does it implement?

b$.)$ Assuming $0$ and $2\mathrm{.}5$ V inputs, size the PMOS transistor to achieve a $V_{OL}=0\mathrm{.}3V.$

c$.)$ If the PMOS were removed, would the circuit still function correctly? Does the PMOS transistor serve any useful purpose?