Why is it not preferable for a firewall to treat each network frame or packet in isolation?

A.
Such a firewall has no way of knowing if any given packet is part of an existing connection, is
trying to establish a new connection, or is just a rogue packet.

B.
Such a firewall is costly to setup.

C.
Such a firewall is too complicated to maintain.

D.
Such a firewall is CPU hungry.

E.
Such a firewall offers poor compatibility.

F.
None of the choices.

Explanation:
A stateless firewall treats each network frame or packet in isolation. Such a firewall has no way of
knowing if any given packet is part of an existing connection, is trying to establish a new connection,
or is just a rogue packet.