Ans. (C). primary producers make organic matter using inorganic nutrients and energy, while primary consumers eat primary producers.
A food web diagram represents a natural interconnection between organisms of an ecosystem to show what-eats-what in that ecosystem.
Primary producers are autotrophic, photosynthetic organisms that make their own food, in the form of organic compounds, by using inorganic substances, water and carbon dioxide. Examples of primary producers include green plants.
Primary consumers are heterotrophic organisms that cannot nake their own food. They are herbivorous organisms that feed on primary producers. Examples: deer, cow, and rabbit.
Thus, the correct answer is option (C).