Consider the following Karnaugh map:

Which term represents Group $1?$

a$.$

$BD$

b$.$

$A^{\text{'}}BD$

C$.$

ABD

d$.$

B

Which one of the following regarding the circuit is TRUE?

a$.$

Gates $1$ and $3$ are OR gates, and Gate $2$ is an AND gate.

b$.$

Gates $2$ and $3$ are NOR gates, and Gate $1$ is an OR gate.

C$.$

Gate $1$ is an OR gate, gate $3$ is an NOR gate and gate $2$ is a NAND gate.

d$.$

Gate $1$ is an OR gate, gate $3$ is an XOR gate and gate $2$ is a NAND gate.