The best approach for restarting a home network when it's failing is:
First the modem, then the router, then computers.
So, the correct option is: First the modem, then router, then computers.
This method ensures that the modem establishes a connection to the internet before the router starts distributing that connection to the devices on the network. After the router is up and running, the computers can then be restarted to connect to the network properly.