Final answer:
The phrase often used in conditional probabilities is 'given that'. Conditional probabilities refer to the likelihood of an event occurring given that another event has already occurred.
Step-by-step explanation:
The phrase often used in conditional probabilities is b) 'given that'. Conditional probabilities refer to the likelihood of an event occurring given that another event has already occurred. For example, if we have the probability of event A given that event B has occurred, it is written as P(A|B).