Task: Wrong Candidate Generation
Input (English): 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 ? 
Correct Answer: The scientists believe that the material is light .
Output (English): The scientists believe the material is cost - effective .