Subject: mathqa
Question: oil is poured into a tank so that the tank is being filled at the rate of 4 cubic feet per hour . if the empty rectangular tank is 9 feet long , 8 feet wide , and 5 feet deep , approximately how many hours does it take to fill the tank ?
Option: 
A: 60', 'b ) 70', 'c ) 80', 'd ) 90', 'e ) 100']
B: 100']
C: 70', 'c ) 80', 'd ) 90', 'e ) 100']
D: 90', 'e ) 100']
Answer: D