Here's a problem to solve: A lake that received runoff from surrounding farmland had a healthy fish population. Several years ago, a new type of pesticide was used to treat crops. As runoff entered the lake, it killed an insect that was a primary food source for fish. Which will most likely occur if farmers in the area stop using the pesticide?

Among the 4 following options, which is the correct answer?

- A: The population of fish will increase.
 
- B: The insects will become more resistant to the pesticide.
 
- C: The lake will be unable to support life.
 
- D: The fish will find another food source.
 