下列各组物质，只用组内溶液互相混合的方法，就能鉴别的是 请选择ABCD6B9a/E,f*W1?:A4_3d9i2l0J'W7B.O2f/n+^
A. Na2SO4. BaCl2. KNO3. NaCl4_3d9i2l0J'W7B.O2f/n+^
B. Na2SO4. BaCl2. Na2CO3. HCl4_3d9i2l0J'W7B.O2f/n+^
C. NaOH. Na2SO4. CuSO4. MgCl24_3d9i2l0J'W7B.O2f/n+^
D. NaCl. AgNO3. NaNO3. HCl4_3d9i2l0J'W7B.O2f/n+^