Polymorphism is shown by
A) Physalia
B) Termite
C) Trypanosoma
D) All of the above

Hint: Polymorphism is the occurrence of several forms or types of individuals among the members of a single species. It occurs due to discontinuous genetic variations.

Complete answer:
To answer this question, we must know about polymorphism and the organisms in which it occurs.
Polymorphism means occurrence of two different forms. Polymorphism is defined as the different forms of phenotype arising from the same genotype. These morphs occupy the same habitat at the same time. The different phenotypes are called zooids. For example in jaguar, there is one possible trait for skin colouring light or dark. Due to having more than one possibility, it is called polymorphism. It is common in nature and leads to biodiversity, genetic variations and adaptations. The process of polymorphism is inheritable. Polymorphism is shown by phylum protozoa, cnidaria,
Phylum Protozoans- Trypanosoma gambiense exhibit six polymorphic forms which are named on the basis of origin, flagella and body structure.
Phylum cnidaria class hydrozoa exhibit polymorphism. They have two polymorphic forms. Polyp has a tubular body, reproduces asexually and is sessile. Medusa has an umbrella-like body, reproduces sexually and is motile.
Termites-In termites, the different individuals or zooids are grouped into different castes like queen, workers, and soldiers. They live together forming a large community.

Thus the correct answer is (D) All of the above.

Note:Polymorphism is heritable. Multiple phenotypes of a species occur at the same time. It leads to genetic variation. Human ABO blood group is an example of polymorphism.