congruence and similarity

The Answer is B. S.S.A.

圖片參考：http://i281.photobucket.com/albums/kk202/eg_slt2003/Yahoo7008050502844.jpg

Consider △AOB and △AOC,
AO = AO (common side)
OB = OC(radius of the same circle)
∠OAB = ∠OAC(common angle)
These two triangles satisfy the S.S.A. conditions. However there are not congruent triangles.

2008-05-06 10:33:27 補充：
「there」→「they」

which of the following is not a condition for congruent triangles?
A.S.A.S
B.S.S.A
C.A.S.A
D.A.A.S
the reference website illustrates why S.S.A is not a condition for congruent triangles