He was ill in hospital. His teacher looked after him                        .           [ ]

A. as good as possible            

B. as soon as possible            

C. as well as possible            

D. as better as possible

洞庭碧螺春，又叫“吓煞人香”，是中国十大名茶之一，泡茶后奇香扑鼻，汤色碧绿、卷曲如螺．由于茶叶中富含咖啡碱（化学式为：C₈H₁₀N₄O₂），对人体具有兴奋、减肥、利尿、强心解痉等保健作用，深受人们的喜爱．下列叙述中错误的是（　　）

A．咖啡碱由C、H、O、N四种元素组成

B．闻到茶香说明分子在不断运动

C．咖啡碱属于有机物

D．咖啡碱中氢元素的质量分数最大