称取含磷样品0.1000g,溶解后把磷沉淀为MgNH4PO4.此沉定过滤洗涤再溶解,最后用0.01000md/L的EDTA标准溶液滴定,消耗20.00mL.样品中P2O5的百分含量为（）。已知M(MgNH4P04)=137.32g/mol,M(P2O5)=141.95g/mol.

称取含磷样品0.1000g,溶解后把磷沉淀为MgNH4PO4.此沉定过滤洗涤再溶解,最后用0.01000md/L的EDTA标准溶液滴定,消耗20.00mL.样品中P2O5的百分含量为（）。已知M(MgNH4P04)=137.32g/mol,M(P2O5)=141.95g/mol.
A.13.79%
B.14.20%(正确答案)
C.27.46%
D.28.39%