The average mass of $$2$$ bags of flour is $$1.72 \text{kg}$$. The mass of one of the bag of flour is $$1.68 \text{kg}$$. What is the mass of the other bag of flour? 
选项为:A:$$1.76kg$$  B:$$3.44kg$$  C:$$1.68kg$$  D:$$1.72kg$$  请回答其中一个选项.