A person travels in a car for 600 km at an average speed of 50 km/h and 100 km at 100 km/h, and finally reaches his destination by travelling 50 km at a speed of 25 km/h. Determine the average speed during the whole journey

A

50 km/h

B

75 km/h

C

58.33 km/h

D

25 km/h