14. The average speed v and molecular diameter d of five ideal gases are given below. The number of molecules per unit volume is the same for all of them. Which gas has the greatest mean free path? (A) v = 4v₀ and d = d₀/5 (B) v = 2v₀ and d = d₀/3 (C) v = v₀ and d = d₀ (D) v = v₀/2 and d = 3d₀ (E) v = v₀/4 and d = 5d₀