Explanations Are Good Just in Case Understanding Is Increased

Multiple Choice

Explanations are good just in case understanding is increased. Understanding is not increased if, and only if, explanations are empirical deductions. So, explanations are good if, and only if, they are not logical deductions.
-Which of the following propositions is not derivable from the given premises using any of the twenty-five rules of PL and either the direct or conditional methods of proof?

A) ∼D ⊃ ∼E
B) D ≡ ∼E
C) E ⊃ ∼D
D) ∼D ≡ E
E) D ⊃ ∼E