阅读下列四篇短文，从每小题后所给的A,B,C或D四个选项中，选出最佳选项。
You know eating fruit and vegetables does good. But do you know it can also make you look good? People who increased their intake over just six weeks developed a healthy glow and appeared more attractive, researchers found. Scientists at St Andrews University found eating them slightly increased yellow and red pigments in the volunteers' skin. They monitored the food intake of 35 people and took pictures of their faces, arms and hands using a sensitive camera at the start, and after three and six weeks. Increasing their intake of greens by 2.9 portions a day was found to make the person look more healthy and an extra 3.3 portions could enhance their attractiveness, when their photographs were rated by others.
Fruit and vegetables are rich in carotenoids(类胡萝卜素)，which are known to protect against cell damage from pollution and UV rays, and can also prevent age-related diseases including heart disease and cancer. But while it was known eating extreme amounts of certain vegetables such as carrots could turn skin orange，it was not known a small increase was perceptible(被觉察）to others—and was seen as appealing.
