Possible answers: [I] sunlight. [II] vegetation. [III] Energy. [IV] loose soil. [V] plant life. [VI] diatoms. [VII] fungi. [VIII] chemicals.
Given those answer options, answer the question: Fact 1: Zooplankton are tiny animals that feed on phytoplankton. Fact 2: Diatoms are the predominant phytoplankton. Given the two facts above, zooplankton are tiny animals that feed on what?
A:
[VI]