An Environmental Scientist Is Least Likely to Be Involved with Which

An environmental scientist is least likely to be involved with which of the following?

A) studying X -ray emissions for evidence of black holes
B) studying the relationship between soil fungi and aspen trees in areas that are being restored after oil sand mining
C) helping a rancher determine the best ways to rotate herds of cattle to reduce erosion
D) determining the best fuel to generate electricity for a growing city in Arizona
E) launching NASA satellites that monitor changes in carbon dioxide production on Earth