which portion of the frame is the 802.1q header found?

In which portion of the frame is the 802.1q header found?

A.
within the Ethernet header

B.
within the Ethernet payload

C.
within the Ethernet FCS

D.
within the Ethernet source MAC address

Explanation:
Frame format

Insertion of 802.1Q tag in an Ethernet frame

802.1Q does not encapsulate the original frame. Instead, for Ethernet frames, it adds a 32-bit field between the source MAC address and the EtherType/length
fields of the original frame
http://en.wikipedia.org/wiki/IEEE_802.1Q