Final answer:
The conclusion that follows in a single step from the given premises is ∼C ⊃ ∼E 2, 3, HS.
Step-by-step explanation:
The conclusion that follows in a single step from the given premises is option c. ∼C ⊃ ∼E 2, 3, HS.
- Step 1: Apply the Hypothetical Syllogism (HS) rule by using premise 2 (R ⊃ ∼E) and premise 3 (N ⊃ (∼C ⊃ R)). By replacing R with ∼E from premise 2, we can infer ∼C ⊃ ∼E.