What is required for a LAN switch to support 802.1q Q-in-Q encapsulation?

What is required for a LAN switch to support 802.1q Q-in-Q encapsulation?

A.
Support less than 1500 MTU

B.
Support 1504 MTU or higher

C.
Support 1522 layer 3 IP and IPX packet

D.
Support 1547 MTU only