No. See 230.40 exception 2.
This is kind of a trick question though. A service conductor can never really be "tapped", since there is no way to meet the definition of a tap with a service conductor in 240.2. The only true "taps" allowed in the NEC are for feeders and (under rare circumstance) branch circuits.
If you are asking if you can install a second set of service entrance conductors on one service, the answer is yes, using the above cited reference. Be careful to satisfy the requirement of conductor per terminal in 110.14, as I have not seen a meter enclosure that has provisions for two condutors per leg and per nuetral.
I would answer "D" and then I would jot down the question number to use as a challenge in case you get it wrong, citing 240.2, definition.
[This message has been edited by Ryan_J (edited 10-19-2004).]
Salt Lake City