下列化学方程式正确的是 请选择DCBA1?:K,A+c4m6g1t+p/w0r(U,b+H
A．4Fe+3O22Fe2O34m6g1t+p/w0r(U,b+H
B．2Ag+FeSO4===Fe+Ag2SO44m6g1t+p/w0r(U,b+H
C．2NaCl+K2CO3===Na2CO3+2KClCl4m6g1t+p/w0r(U,b+H
D．Cu+2AgNO3===Cu（NO3）2+2Ag4m6g1t+p/w0r(U,b+H