In this task, you need to provide the correct option for a given problem from the provided options.
Q: Problem: the present ages of reena and usha are 24 and 36 yr . respectively . what was the ratio between the ages of usha and reena respectively 8 yr ago ?
Options: a ) 7 : 4 , b ) 4 : 7 , c ) 11 : 8 , d ) 8 : 11 , e ) 9 : 12
A:
a