What quantity of water should taken out to concentrate 27 liters of 40% acidic liquid to 60% acidic liquid?  Select the correct option:
A) 5 liters	B) 10 liters	C) 15 liters	D) 9 liters	E) 6 liters

Rationale: "required answer is = 27 ( 60 - 40 ) / 60 = 9 liters answer is d"
Answer: D