A train travelling with constant speed crosses a 80 m long platform in 10 seconds and a 105 m long platform in 12 seconds. Suppose that L denotes the length (in metres) of the train and S denotes the speed (in km/hr) of the train. Then :
A. L = 30, S = 40
B. L = 45, S = 45
C. 10% of 20% of $\frac{2}{3}\text{rd}$ of L = $\frac{3}{5}$
D. 50% of S = 22.5
Choose the correct answer from the options given below :