Task: Question Answering
Input (English): Problem: elvin ' s monthly telephone bill is the sum of the charge for the calls he made during the month and a fixed monthly charge for internet service . elvin ' s total telephone bill for january was $ 48 and elvin ' s total telephone bill for february was 90 $ . if elvin ' s charge for the calls he made in february was twice the charge for the calls he made in january , what is elvin ' s fixed monthly charge for internet service ? 
Options: a ) $ 5 , b ) $ 10 , c ) $ 14 , d ) $ 6 , e ) $ 28
Output (English): d