Correct Answer: (b) 2 and 3
Solution:Copepods are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Copepods are major zooplankton. Some of the larger species are predators of their smaller relatives. Many benthic copepods eat organic detritus or the bacteria that grow in it. Many copepods (e.g., fish lice like the Siphonostomatoida) are parasites, and feed on their host organisms.
Cyanobacteria, also called bluegreen algae, are microscopic organisms found naturally in all types of water. Cyanobacteria are important primary producers and form a part of the phytoplankton. They use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light.
Diatom refers to any member of a large group comprising several genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. They are especially important in oceans, where they contribute an estimated 45% of the total oceanic primary production of organic material.
Foraminifera are amoeba-like, single-celled protists (very simple micro-organisms). They are characterized by streaming granular ectoplasm for catching food and other uses, and commonly an external shell (called a "test") of diverse forms and materials.