In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Example Input: Problem: how many seconds will a train 110 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph ? 
Options: a ) 28 sec , b ) 23 sec , c ) 24 sec , d ) 25 sec , e ) 26 sec
Example Output: e

Example Input: Problem: a tank with a volume of 20 cubic feet has one inlet pipe and 2 outlet pipes . the inlet pipe fills water into the tank at the rate of 5 cubic inches / min and the 2 outlet pipes empty it out at the rates of 9 cubic inches / min and 8 cubic inches / min respectively . if all 3 pipes are opened when the tank is full , how many minutes does it take to empty the tank ? ( 1 foot = 12 inches ) 
Options: a ) 2110 , b ) 2220 , c ) 2440 , d ) 2660 , e ) 2880
Example Output: e

Example Input: Problem: how many 4 digit numbers are there , if it is known that the first digit is even , the second is odd , the third is prime , the fourth ( units digit ) is divisible by 7 , and the digit 2 can be used only once ? 
Options: a ) 20 , b ) 150 , c ) 225 , d ) 300 , e ) 320
Example Output:
b