Answer:
D. Agronomist
Step-by-step explanation:
Agronomists are professionals that study how to make soils more productive (in terms of food) around the world. Soil pH is an index that calculates the acidity/alkalinity of the soil, which is indicated on a 14-point scale (pH equal to 7 = neutral; pH below 7 = acidic, pH higher than 7 = alkaline). In this regard, it is well known that the pH of the soils drastically affects plant development, and thereby a proper soil pH is fundamental to ensure optimal plant growth (required for nutrient intake). For this purpose, agronomists are in charge of studying and researching the pH of the soils in order to increase crop yields. Nowadays, the pH of the soils can be easily measured by digital soil pH pocket testers that utilize a pH electrode in order to calculate the pH value.