The paragraph talks about how geological events occur in a cycle, and research has found the period of the cycle to be around27.5millionyears. It also mentions that mass extinctions occur at this 27.5millionsyears, too. From this we can see that geological events and mass extinctions both occur around the same time and thus are correlated to each other. Hence, Option E is the answer. Option A: the passage mentions that mass extinctions happen every 27.5millionyears, but it is not the main idea of the passage. Option B: The passage says that the length between pulses is 26.2 and 30.6millionyears and in general occurs around 27.5millionyears.Thus, it is not a constant value. Option C: It is incorrect since the paragraph only talks about mass extinction. Whether all species go extinct or not is not mentioned. Option D: The passage is talking about geological events occurring in a cycle. Hence, it is incorrect.