The first answer is correct, the second one is D.
A tolerance range is an environment where something can survive in. But if their is to much of one factor or to little this can effect the tolerance range.
Magnetite, Pyrrhotite, Hematite, Earth, Magnetar
Answer: E. reforestation
Explanation:
Reforestation is a process of planting trees in an area so as to conserve the land as future forest. According to the given situation, reforestation is the practice which can be used by the biologists to grow nitrogen fixing plants in an area so as to increase the nutrient concentration of the soil which have been depleted.