Can Every Syllogism with a Missing Conclusion Be Completed in Such

Can every syllogism with a missing conclusion be completed in such a way as to produce a valid syllogism?

A) No, since there might be no connection between the two premises.
B) No, since the premises might not both be categorical.
C) No, since two universal premises could not validly lead to any conclusion.
D) Yes, since any two premises can validly lead to an I conclusion.
E) Yes, since even if the two premises are completely unrelated, they would validly lead to an E conclusion.