Question 10 is based on the following stews. At the end of the stews item, you will be given 10 seconds to answer the question. Now listen to the stews.

A．There are two groups of engineers who are working on the alternative solutions of the program.
B．Discovery’s protective heat tiles ate out of order.
C．NASA has made the decision on whether anything needs to be done about the gap fillers.
D．According to NASA there is only a problem with Discovery and it can return to the earth safely.