フリー問題

問題文

A site is told that the service never opens a protected exchange, so an engineer wants to know what is left to work with. The engineer asks what the firewall lines the far side's token up against on the spot, and what sort of description of the exchange it then sends onward. What does it send up?

選択肢

1. Engineers run the signature check on that exchange and pass the timing pattern up to the service.
2. Engineers run the signature check on that exchange and pass the sequence pattern up to the service.
3. Engineers run the protocol check on that exchange and pass the timing pattern up to the service.
4. Engineers run the protocol check on that exchange and pass the sequence pattern up to the service.