Your friend John is having trouble with his compost bin. The material in his compost pile doesn't seem to be decomposing well You take a sample of the pile and check for the presence of microorganisms under the microscope. You see that there are indeed microorganisms, however they don't appear to be growing very fast John says that he regularly mixes his compost pile to expose it to oxygen What is the most likely explanation for this problem?

The temperature may not be high enough to encourage microorganism growth
Inorganic materials may have been included in the compost pile
The temperature may be too high for microorganisms to tolerate
Inappropnate food waste may have been included in the compost pile