I wouldn't suggest using hypothetical solutions to prove that an answer cannot be true, although you could use them to prove that some things could be true. For example, if you had answer B as a contender, you might try drawing out a solution in which P was earlier than G. That would mean we would have a sequence of M
P
G, which would place M at 1:00, P at 2:00, and G at 3:00. That could look like this:
West: M P S
East: U O G
(There may be other solutions that would also work, but all we have to do to prove that an answer to a Cannot Be True question is wrong is to show that it Could Be True in at least one case.)
For answer A, my suggestion would be to diagram the answer and see what it looks like. If we try to put G before M, when we couple that with the rule about U and G we get this sequence:
U
G
M
This cannot be true because M must be before both O and P, and this sequence makes that impossible by placing M at 3:00. There's no need for a hypothetical solution here, and no hypothetical solution would work in any case. Just a quick diagram of the answer choice in connection with the original rules reveals that it cannot be true and is therefore correct.
Adam M. Tyson
PowerScore LSAT, GRE, ACT and SAT Instructor
Follow me on Twitter at
https://twitter.com/LSATadam