How can an existing computer group be deleted?

A.
Tools > Remove Computer Group

B.
drag the computer group to the Trash

C.
right-click on the existing computer group and select Remove

D.
Computers > By Group, right click on the existing computer group and select Remove

Explanation:
http://pic.dhe.ibm.com/infocenter/tivihelp/v26r1/topic/com.ibm.tem.doc_8.2/Tivoli_Endpoint_Manager_Console_Operators_Guide.pdf (page 81)