单选题Host A opens a Telnet connection to Host B. Host A then opens another Telnet connection to Host B. These connections are the only communication between Host A and Host B. The security policy configuration permits both connections. How many flows exist

Host A opens a Telnet connection to Host B. Host A then opens another Telnet connection to Host B. These connections are the only communication between Host A and Host B. The security policy configuration permits both connections. How many flows exist between Host A and Host B? （）