A network address is $131\mathrm{.}247\mathrm{.}160\mathrm{.}0/19.$ The $19$ implies that

A$.$

$19$ bits are reserved for the host part of IP addresses on the network

B$.$

$19$ bits are reserved for the network part of IP addresses on the network

C$.$

There are $19$ subnets in the network

D$.$

There are $19$ IP addresses available on the network