You created a route in route table RT1 and must specify the next hop by IP address. Which next hop type should you choose?

The correct next hop type is Virtual appliance. When you want to route traffic to a specific IP address within your Azure network, often to a network virtual appliance (NVA) like a firewall or a load balancer, you select "Virtual appliance" as the next hop type. This allows you to specify the private IP address of that appliance as the destination for the route. "Internet" is used for traffic destined outside your Azure virtual network to public IP addresses. "Virtual network gateway" is for routing traffic through an Azure VPN Gateway or ExpressRoute Gateway to on-premises networks or other virtual networks. "Virtual network" is a default route that allows communication within the virtual network and is not typically specified manually for a custom route to a specific IP.