In the Following Proof, Which Justification Is Correct for Line

Multiple Choice

In the following proof, which justification is correct for line 3? $\begin{array}{llcc} \text { (1) \( (x) [(\mathrm{C} x * \sim \mathrm{D} x) \supset \mathrm{E} x] \) } & & \text {Premise } \\ \text { (2) \( (x) (\mathrm{E} x \supset \mathrm{D} x) \) } & \text { \(/(x) (C x \supset D x) \) }& \text { Premise/Conclusion } \\ \text {(3) \( \mathrm{Ca} \) } &\\\end{array}$

A) 1 UI
B) 1 Simp
C) Assumption
D) RA
E) None of these answers are correct.