"XOR gate is a digital logic gate that gives a true output when the number of true inputis odd."

a$)$ Design NAND gate using transistors and briefly explain. $(10$ points$)$

b$)$ How can XOR gate be designed using NAND Gates? Explain. $(30$ points$)$

$($Hints: $\{$:$(A^{\text{'}}{)}^{\text{'}}=A,$ A xor $B=A^{\text{'}}B+A{B}^{\text{'}})$