Answer:
C
Step-by-step explanation:
Acidic soils mean they have more of Al3+ and H+ ions which are acid forming cations. These cations make alkaline forming ions unavailable to plants as nutrients. When the pH of the soil is raised, the Al3+, Fe3+, and H+ are neutralized. The ions bind with –OH ions hence releasing the ions in the negatively-charged sites on the hummus to play a role in the nutrient exchange.