A container originally contains 10 litres of pure spirit. From this container 1 litre of spirit is replaced with 1 litre of water. Subsequently, 1 litre of the mixture is again replaced with 1 litre of water and this process is repeated one more time. How much spirit is now left in the container?
(A) 7.58 litres
(B) 7.84 litres
(C) 7 litres
(D) 7.29 litres