单项选择题
A.5,7,4’-三羟基黄酮 B.5,7,3’,4’-四羟基黄酮 C.3,5,7,4’-四羟基黄酮 D.3,5,7,3’,4’-四羟基黄酮 E.3,5,7,3’,4’,5’-五羟基黄酮
A.5%NaHCO3 B.5%Na2CO3 C.0.2%NaOH D.4%NaOH E.5%HCl