阅读下列短文，从每题所给的四个选项（A、B、C、D）中，选出最佳选项。
When most of us look at our hands, we might notice that we need to clean, or stop biting our fingernails, and that’s about it. But if you ask a doctor, he can see a whole lot more. Everything from poor diet and stress to serious kidney (肾) problems can be revealed by a glance at your fingernails.
There are about 30 different nail signs that can be associated with medical issues, though may indicate more than one problem, according to Dr.Amy Derick, a clinical instructor of dermatology at Northwestern University.
Here are five of the things a doctor can tell about your health based on your fingernails.
1. People who aren’t eating well and lack vitamin or dietary may have thinner than normal nails, which are more likely to break.
2.Horizontal (水平的) lines are associated with serious physical stress. They frequently occur in people who have gone through chemotherapy(化疗).They can also occur after some illnesses, injuries, or with severe malnourishment(营养不良).Interestingly, there may be an altitude connection too. They’ve also been found in people who dove 1,000 feet and others who participated in an Everest exploration.
