Hey there!
Your answer: Available Space
The question is asking, which of the following options would be a (limited source). We have to find a option that has a limited source, which means that there is a limit to something. Your answer is (b) because there are limited space with the spce that is already available. Air temperature would NOT be your answer.
Answer:
Some phytoplankton are bacteria, some are protists, and most are single-celled plants. Among the common kinds are cyanobacteria, silica-encased diatoms, dinoflagellates, green algae, and chalk-coated coccolithophores.
Explanation:
You be the battery, I'll be the aluminum foil and together we'll light up the world.