Answer:
A. The temperatures are too high.
Step-by-step explanation:
A desert is a region with extremes of temperatures and little to no rainfall.
Organic matter are the remains of organisms that have died. They are a very important component of soils.
Where temperatures are very extreme, there would be little to no life. Only special organisms that have evolved to adapt will survive such region.
Due to the low amount of plant and animal lives owing from the high temperature of deserts, little to no organic matter forms.