Concept:The Earth rotates 15∘ in 1 hour, so longitude differences create time differences. Locations to the west have earlier times.Explanation:Town X lies on 15∘E, while town Y lies on 15∘W.Total longitude difference =15∘+15∘=30∘.Time difference =30∘÷15∘=2 hours.Since town Y is west of town X, the local time in Y is behind.Time in Y =4.00 pm−2 hours=2.00 pm.Answer:B. 2.00 pm