It's chemoautotrophs because cyanobacteria can be mixotrophic if needed and they are classified as algae.
Answer:
Study it under a microscope!
Explanation:
Any organisms in the pond water are more than likely very, very small! Microscopic, even;)
A process in which something passes by degrees to a different stage (example: plants, animals, humans, etc)
The answer would be C because iron is magnetic