They can be tested at the same time. They can be produced in large numbers. They will be bought by many different users. They will be sold for more than they cost to build.
I gave my students this multiple choice question: A company is making prototypes for a new computer system. Which of the following statements best describes an advantage of making several different prototypes?

Only one answer is correct among these 4 choices:
- They can be tested at the same time.
- They can be produced in large numbers.
- They will be bought by many different users.
- They will be sold for more than they cost to build.

Could you tell me which one is correct?

They can be tested at the same time.