A fruit juice recipe calls for 2 parts orange juice and 8 parts pineapple juice. Which proportion can be used to find the amount of orange juice, j, that is needed to add to 18 L of pineapple juice?

2 over 8 equals j over 18
8 over 2 equals j over 18
8 over j equals 2 over 18
16 over 18 equals j over 100