Aand b are two events. the notation for conditional probability is p(b|a) . which notation is the probability of two events being not independent?

a. p(b|a) = p(a and b) / p(a)
b. p(b|a) = p(a) / p(b)
c. p(b|a) = p(b)
d. p(b|a) = p(b) / p(a)