单项选择题

A、Z[E1(s)E2(s)]=E1(z)E2(z)
B、Z[E1*(s)E2(s)]=E1(z)E2(z)
C、Z[E1*(s)E2(s)]=E1E2(z)
D、Z[E1(s)E2(s)]=E2(z)E1(z)