Which Rule Is Used in the Following Inference $$\begin{array} { l } ( A \cdot B ) \supset ( C \supset D ) \\A \cdot B \\C \supset D \end{array}$$

Multiple Choice

Which rule is used in the following inference? $$\begin{array} { l } ( A \cdot B ) \supset ( C \supset D ) \\A \cdot B \\C \supset D \end{array}$$

A) HS
B) MP
C) MT
D) CD
E) DD