A vessel contains some amount of pure milk. 8 litres of water is added to dilute the milk, after taking out 8 litres of pure milk. Once again 8 litres of the resulting mixture is removed and 8 litres of water is added. The amount of pure milk in the second mixture is 49 litres. What amount of pure milk was in the container originally ?

A

80 litres

B

100 litres

C

64 litres

D

72 litres