REVIEW FOR FINAL

The answer is E but why is this the correct answer?

explain how this is determined and why

Risk and Return Which of the following could be characterized as a systematic risk event? a) The CEO and founder of a young, successful corporation dies unexpectedly b) Economic recession c) Merck, a pharmaceutical company, is sued because it's best selling arthritis medication is found to cause heart attack and stroke. d) War e) Both b and d