An aeroplane flies with an average speed of 756 km/h . A helicopter takes 48 h to cover twice the distance covered by aeroplane in 9 h . How much distance will the helicopter cover in 18 h ? (Assuming that flights are non-stop and moving with uniform speed)
A. 5010 km
B. 4875 km
C. 5760 km
D. 5103 km