A layer$-4$ firewall $($a device that can look at all protocol headers up to the transport layer$)$ CANNOT

Answer

$1)$block entire HTTP traffic during $9$:$00$ PM and $5$:$00$ AM

ii$)$block all ICMP traffic

iii$)$stop incoming traffic from a specific IP address but allow outgoing traffic to the same IP address

iv$)$block TCP traffic from a specific user on a multi$-$user system during $9$:$00$ PM and $5$:$00$ AM$.$