A Researcher Carries Out an Experiment During the Summertime in New

A researcher carries out an experiment during the summertime in New England. He plants cacti on two adjacent pieces of land that are identical, except for the fact that one piece of land has been cleared of all other vegetation. He notices that cacti planted on the cleared land take root and grow, whereas those planted on the uncleared land don't. What is a likely explanation?

A) By clearing one piece of land and disturbing the soil, the researcher has recapitulated the sandy environment where cacti typically grow.
B) Microorganisms in the soil of the cleared land likely infect cacti roots.
C) Animals have easier access to cacti in the uncleared land.
D) Other plants likely compete with cacti for resources on the uncleared land.
E) All of these choices are correct.