$10.$ Which statements regarding IPv$4($Internet Protocol version $4)$ or IP are INCORRECT $($More than one statement applies$)?$

a$.$

IP is a Network access$-$layer protocol.

b$.$

IP is a connection$-$oriented protocol, so it is efficient and reliable.

c$.$

IPv$4$ defines a $64-$bit dotted decimal address.

d$.$

The protocol field in an IP header is a numeric code specifying the type of IP packet or the next$-$layer protocol contained in the packet.