B
Below is a question with multiple-choice answers. Choose the correct option based on your reasoning.

### Question:
A drinking water reservoir for a small town develops a blue-green algae bloom. The town hires a company to eliminate the problem. Which of the following should the company investigate first as a likely source of the problem?

### Choices:
A. a pit where granite is ground up into gravel
B. a neighborhood where lawn chemicals are used
C. a junkyard where old cars are salvaged for parts
D. a grain elevator where corn and soybeans are stored

### Answer:
