Switch R1 has been configured with DTP using the desirable option. Which statement describes Dynamic Trunking Protocol （DTP） desirable mode？（）
- A The interface actively attempts to convert the link to a trunk link.
- B The interface is put into permanent trunking mode but prevented from generating DTP frames.
- C The interface is put into permanent trunking mode and negotiates to convert the link into a trunk link.
- D The interface is put into a passive mode， waiting to convert the link to a trunk link.
- E None of the other alternatives apply