▲閱讀下文，回答第 41−45 題The days are getting shorter while the nights are getting longer as the winter approaches in Northern Europe. From October to March, the only resource the Nordic countries seem to enjoy in abundance is darkness. For anyone who has experienced a Nordic winter, it won’t come as a surprise that light plays a major role in influencing people’s body and mood. Some people inthese countries eat more, sleep more, and feel depressed during this period of time; they are back to normal by April. This pattern repeats itself year after year. In fact, there is an interesting body of research investigating this pattern. Researchers believe that those people suffer from a condition called “ Seasonal Affective Disorder,” or SAD. This is a type of depression that comes with insufficient light exposure. Its symptoms include fatigue, depression, irritability, increased appetite, and weight gain. According to the researchers, anyone can be influenced by SAD, but it more often has impacts on women. The good news is: there are treatments for SAD. For those with mild cases, their symptoms can be improved just by brightening the rooms in their houses and getting more exposure to sunlight. More severe SAD sufferers may need to receive treatment. They can find relief with a new light treatment by getting 30 minutes to a few hours a day of extra exposure to light from special equipment during the winter months. This new light treatment is changing the lives of SAD sufferers. With increases in their exposure to either natural or artificial light, about 3/4 of SAD sufferers have improved. They can now enjoy the seasonal changes, just as most of us do.
41. What is the cause of “Seasonal Affective Disorder ”?
(A) Gaining appetite.
(B) Getting light treatment.
(C) Lacking light exposure.
(D) Losing weight.