Answer: A or C
The probability of every event is at least zero.
(For every event A, P(A) >= 0. There is no such thing as a negative probability.)
The probability of the entire outcome space is 100%.
(P(S) = 100%. The chance that something in the outcome space occurs is 100%, because the outcome space contains every possible outcome.)
If two events are disjoint, the probability that either happens is the sum of the probabilities that each happens.
(If AB = {}, P(AUB) = P(A) + P(B).)
Explanation:
the probability that an event A does not happen is 100% minus the probability that A happens:
My answer P(Ac) = 100% - P(A).