Final answer:
A biconditional statement with contingencies on both sides cannot be a tautology because the truth of a tautology does not depend on contingencies, hence the answer is False.
Step-by-step explanation:
A biconditional statement in logic is a statement of the form "P if and only if Q" where P and Q are statements. For a biconditional to be a tautology, it must be true in all possible scenarios. However, if P and Q are both contingencies - statements that can be either true or false depending on the scenario - the biconditional is not guaranteed to be a tautology. A contingency might take the form of an event with a probability, such as Event T (the outcome is two) or Event A (the outcome is an even number).
It's important to understand notions like mutual exclusivity and independent events to analyze the probability of such events. In the case of Event A and Event B (the outcome is less than four), one must check if they are mutually exclusive or not - they cannot both be true at the same time, as demonstrated in Event A GIVEN B and Event B GIVEN A. The concepts of necessity and sufficiency play a role here as well; one event might be a necessary or sufficient condition for the other.
In light of this, the correct answer to the question is False. A biconditional that has a contingency on the left and another contingency on the right might be contingent itself, but not a tautology, as the truth value of a tautology does not depend on any contingency.