_____ his movie work, Redford is also known as a champion of environmental protection.[ ]

A. Due to                        

B. As to  

C. In addition to                    

D. In spite of

5岁男孩，面色苍白半年入院，间有脐周痛；贫血貌，心率108次／分，律齐、心尖SMⅡ，腹平软，肝0．5cm，WBC8．2×10⁹／L，N0．50，E（嗜酸性粒细胞）0．09，RBC4．0×10¹²／L，Hb80g／L，MCV65fl，大便潜血（++），引起贫血的原因是（）

A.慢性炎症

B.铁缺乏

C.维生素B12缺乏

D.叶酸缺乏

E.再生障碍性贫血