Which of the following IP phone feature needs to be configured to enabled users to send Hookflash to an analog trunk?

Which of the following IP phone feature needs to be configured to enabled users to send Hookflash to an analog trunk?

A.
Flash Softkey.

B.
URL services.

C.
SMTP services

D.
It is enabled by default.

E.
H.450 script on FXS port.