Direction: Read the passage given below and answer the questions that follow by selecting the most appropriate option.

As heart disease continues to be the number one killer in the United States, researchers have become increasingly interested in identifying the potential risk factors that trigger heart attacks. High fat diets and life in the fastlane have long been known to contribute to the high incidence of heart failure. But according to new studies, the list of risk factors may be significantly longer and quite surprising.

Heart failure appears to have seasonal and temporal patterns. A higher percentage of heart attack occurs in cold weather and more people experience heart failure on Monday than on any other day of the week. In addition, people are more susceptible to heart attacks in the first few hours after waking. Cardiologists first observed this morning phenomenon in mid 1980 and have since discovered a number of possible causes. An early morning rise in blood pressure, heart rate and concentration of heart stimulating hormones, plus a reduction of blood flow to the heart, may all contribute to the incidents of heart attacks between the hours of 8:00 a.m. and 10:00 a.m.