The correct answer is B. Most patients who have a poor dental experience also have post-extraction complications. This can be shown through the fact that of everyone who had a poor dental experience, 94% said they had post-extraction complication. 94% is obviously <em>most</em>. We can not confidently say that poor dental experiences cause post-extraction problems because we do not know how many people who had a normal or good experience also had problems.
The complementary event is that a customer does not enter the store within one minute of closing, and the probability is 75%.
The complement is found by subtracting from 100%; 100-25 = 75%.