Chocolate to Live For! A study published in the Journal of the American Medical Association in 2003 reported that dark chocolate may lower your blood pressure. Researchers at the University of Cologne studied men and women who were recently diagnosed with mild high blood pressure. Half were given 100g (fabout 3.5 ounces) of dark chocolate per day and half were given white chocolate. After only two weeks systolic (收缩的) blood pressure decreased on average by five points and diastolic (以及舒张的) blood pressure by two points in those consuming dark chocolate, but not those consuming white chocolate. In a similar study, researchers from Italy reported in the American Heart Association journal Hypertension that 3.5 ounces of dark chocolate for one week lowered systolic blood pressure by 12 points and diastolic blood pressure by 8.5 points when blood pressure was monitored continuously for 24 hours. Insulin (胰岛素) sensitivity and LDL cholesterol also improved. No benefits were seen with white chocolate. Another study published in the Journal of the American College of Cardiology found that chocolate may help repair damage to smokers’ blood vessels, at least temporarily. why Chocolate increases your body’ s production of nitric oxide (一氧化氮), a powerful substance that causes your blood vessels to relax and dilate. This, in turn, causes an increase in blood flow and a decrease in blood pressure--like opening a water spigot (水龙头). A study published in July in the Journal of the American Medical Association reported that just 30 calories per day of dark chocolate lowered blood pressure and increased nitric oxide production after 18 weeks. Nitric oxide is also stimulated by drugs such as Viagra and Levitra, which increase blood flow to the penis and enhance erections. This may be one of the reasons why chocolate has had a long reputation as an aphrodisiac (壮阳药). Casanova (卡萨诺瓦) is said to have considered it as his "favorite breakfast dish. " Chocolate also contains phenylethylamine (苯乙胺), which research suggests is a stimulant that is released when you’ re interacting with someone intimately. Which of the following statements is true about the subjects in the 2003 study

A. They were all diagnosed with very high blood pressure before they joined the study.
B. They were given 100g of dark chocolate every day for two weeks.
C. Those who had taken dark chocolate had a decrease of systolic blood pressure.
D. All the participants had a decrease of systolic blood pressure and diastolic blood pressur