Answer:
D. Crop plants have shallow root systems, and most of the mineral nutrients are on the surface.
Explanation:
According to the question, we are required to provide the best explanation for the given sentence which says that crop plants make use of more mineral nutrients than native plants.
Based on this sentence, the best explanation would be that crop plants have shallow root systems, and most of the mineral nutrients are on the surface.
I'd say D. expert power because expert power is when an employee ( or in your case the teacher) has a high set of knowledge/skills that other employees do not posses. Which by the information above about this teacher's PhD and thier experience, I assume that this teacher must have expert power.
Answer:
by mutations in regulatory DNA over time
