Which of the Following Define a Complete and Valid Probability

Multiple Choice

Which of the following define a complete and valid probability model?

A) S = {A,B,C};P(A) = 1/3,P(B) = 2/3,P(C) = 1
B) S = {H,T};P(H) = 1/4,P(T) = ³/₄
C) S = {W,X,Y,Z};P(W) = ¹/₄,P(X) = 1/4,P(Z) = ¹/₄
D) P(RED) = 1/2,P(BLUE) = ¹/₂