Answer:
The correct answer is a. phytoplankton.
Phytoplankton is derived from Greek words "phyto" meaning "plant" and "plankton" meaning "made to drift or wander". Hence, these are plant like microscopic organisms that live in large water bodies.
Like plants, they also contain chlorophyll which enable them to capture sunlight and perform photosynthesis.
In contrast, zooplankton (zoo meaning animal like and plankton meaning made to wander) are heterotrophic in nature which consume phytoplankton and other smaller zooplankton.
