Which of the following is in the third trophic level of the food chain?

The correct answer is C, Secondary consumers. In a food chain each step at which energy is transferred is a trophic level, and secondary consumers stand at the third step. The first trophic level is the producers, green plants that make food by photosynthesis; the second is the primary consumers, herbivores that eat plants; the third is the secondary consumers, carnivores that eat the herbivores; and the fourth is the tertiary or top consumers. In the chain grass, grasshopper, frog, snake, eagle, the frog is at the third level. Only about 10 percent of energy passes from one level to the next (Lindeman's ten percent law), so chains rarely go beyond four or five levels. A is wrong because primary consumers are the herbivores of the second level. B is wrong because top consumers sit at the fourth or final level. D is wrong because producers form the first level, the base of every chain. Exam tip: producers 1, herbivores 2, carnivores 3, top carnivores 4.