The total exports and revenues from the exports of a country are given in the two pie charts below.The pie chart for exports shows the quantity of each item as a percentage of the total quantity of exports. The pie chart for the revenues shows the percentage of the total revenue generated through export of each item. The total quantity of exports of all the items is $5$ lakh tonnes and the total revenues are $250$ crore rupees. What is the ratio of the revenue generated through export of Item  $1$ per kilogram to the revenue generated through export of Item $4$ per kilogram?
1. $1:2$
2. $2:1$
3. $1:4$
4. $4:1$