Context: Graphene looks like it \'s going to be one of the " wonder materials " of the future , and a science team at Cornell University have just demonstrated the world \'s smallest balloon made of it .
Question: Why are the scientists so excited about Graphene ?
Option 0: The scientists believe the material is cheap and effective .
Option 1: The scientists believe the material is cost - effective .
Option 2: The scientists believe that the material is light .
Option 3: The scientists believe it is good for armor .
Answer: 2