Final answer:
Quaternary consumers at the fifth trophic level eat tertiary consumers, following the sequence of trophic levels from producers to apex predators.
Step-by-step explanation:
At the fifth trophic level, there would be quaternary consumers that eat tertiary consumers. The sequence of trophic levels typically starts with producers at the first level, followed by primary consumers at the second level, secondary consumers at the third level, tertiary consumers at the fourth level, and finally quaternary consumers at the fifth level. In a food chain, each of these consumers eats the organism at the level directly below it. For example, if a hawk (quaternary consumer) feeds on a snake (tertiary consumer), which in turn feeds on a mouse (secondary consumer) that eats grasshoppers (primary consumers), which feed on grass (producer), the hawk is at the fifth trophic level. Therefore, the correct answer to the question is that quaternary consumers eat tertiary consumers.