There is $480ml$ of water in Jug A and $120ml$ of water in Jug B. How much water must be poured from Jug A into Jug B so that Jug A will have twice as much water as Jug B? 
选项为:A:$$80ml$$  B:$$100ml$$  C:$$240ml$$  D:$$360ml$$  请回答其中一个选项.