You can eliminate A, C, and D almost instantly if you know that engineers are construction workers. The answer is B.
Answer:
Nitrogen fixation is a chemical process by which molecular nitrogen in the air is converted into ammonia or related nitrogenous compounds in soil or aquatic systems. Atmospheric nitrogen is molecular dinitrogen, a relatively nonreactive molecule that is metabolically useless to all but a few microorganisms.
Explanation:
use a mortar & pestle to grind the solute into smaller particles, thus increasing the surface area.
