A car runs 40 minutes at a speed of 45 km/h, next 45 minutes at a speed of 60 km/h and $$1\frac{1}{2}$$ hours at a speed of 50 km/h.
The average speed (in km/h) of the car for the whole journey is closest to:

A

52.8

B

52.3

C

51.9

D

51.4