Concept:Apply the formula Distance=Speed×Time to both parts of the journey and add them.Explanation:Let the initial speed be x km/h.Distance covered in first 2 hours: 2x km.New speed after increase: (x+2) km/h.Distance covered in next 3 hours: 3(x+2) km.Total distance is 36 km, so:2x+3(x+2)=36Simplify:2x+3x+6=365x+6=365x=30x=6Answer:The initial speed is 6 km/h, so the correct option is D.