Question

what windows 10 tool is useful to determine which applications are using network services on a host?
control panel
windows defender firewall
windows explorer
file manager
data usage

Explanation:

Windows Defender Firewall can show which applications are accessing the network. The Control Panel is a general settings hub. Windows Explorer (File Manager) is for file management. Data Usage shows data consumption but not which apps are using network services in a detailed way like the firewall.

Answer:

Windows Defender Firewall