The correct answer is: D. a posterior probability.
Bayes’ theorem is a mathematical formula that calculates the probability of an event (the “posterior probability”) based on prior knowledge of conditions that might be related to the event (the “prior probability”) and new evidence (the “likelihood”).
In the context of the question, the probability of hypothesis (H) specified by P(H) is referred to as a posterior probability because it is the probability of hypothesis H given the evidence E.
An a priori probability is a probability that is assigned to an event before any evidence is observed. A bidirectional probability is a probability that is assigned to an event based on both prior knowledge and new evidence.
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