Refer to the exhibit.  Which statement is true about where trust boundaries should be established  in a network？（）

• A、Endpoints 2 and 3 are optimal places to establish a trust boundary. Endpoint 1 is an acceptable  place to establish a trust boundary.
• B、Endpoint 2 is the optimal place to establish a trust boundary. Endpoints 1 and 3 are acceptable  places to establish a trust boundary.
• C、Endpoint 2 is the only acceptable place to establish a trust boundary.  
• D、Endpoint 1 is the only acceptable place to establish a trust boundary.
• E、Endpoints 1 and 2 are optimal places to establish a trust boundary. Endpoint 3 is an acceptable  place to establish a trust boundary.
• F、Endpoint 1 is the optimal place to establish a trust boundary. Endpoints 2 and 3 are acceptable  places to establish a trust boundary.