A student sets up a compost bin outdoors. Inside the bin microorganisms convert the student’s vegetable and paper scraps into rich fertilizer.Which of the following best describes the role that these microorganisms play in natural habitats?
A The microorganisms help balance the numbers of producers and consumers.
B The microorganisms help keep nutrients cycling through the ecosystem.
C The microorganisms turn solar energy into sugars.
D The microorganisms function as autotrophs.