【单选题】

Questions 15 to 17 are based on the following passage.At the end of the passage, you will be given 15 seconds to answer the questions.

Now, listen to the passage.
What could scientists do if Robert’s theory proves to be trueA．They could drive the insects away.
B．They could keep the plants well-watereD、
C．They could make the plants grow faster.
D．They could build devices to trap insects.