Which ephone-dn type does the exhibit represent?

Exhibit:

Which ephone-dn type does the exhibit represent?

A.
Dual-number ephone-on

B.
Shared ephone-dn

C.
Dual-line ephone-dn

D.
Two ephone-dns with one number

E.
Single-line ephone-dn

F.
Overload ephone-dn