Which statement describes Dynamic Trunking Protocol (DTP) mode ‘desirable’?

Which statement describes Dynamic Trunking Protocol (DTP) mode ‘desirable’?

A.
The interface is put into permanent trunking mode and negotiates to convert the link into a trunk link.

B.
The interface actively attempts to convert the link to a trunk link.

C.
The interface is put into permanent trunking mode but prevented from generating DTP frames.

D.
The interface is put into a passive mode, waiting to convert the link to a trunk link.