单项选择题
下列配方适合于不锈钢等易钝化基体预镀镍的是()。
A.NiSO4·7H2O 240~260g/L,HCl 120~130mL/L
B.NiSO4·7H2O 150g/L,NH4Cl 20g/L,H3BO3 25g/L,pH5.6-5.9
C.NiSO4·7H2O 200~250g/L,NaCl 7~12g/L,H3BO3 20-25g/L,柠檬酸钠50-300g/L,pH7.0~7.2
D.NiSO4·7H2O 120~150g/L,NaCl 7~12g/L,H3BO3 30~45g/L,pH5.0-5.6