Which of these is part of a virus's structure?
A.) genetic material
B.) capsid
C.) protein unit
D.) pili

Genetic material, capsid, protein unit are all parts of a virus's structure.

Explanation:

Structurally, a virus is composed of three main units – the nucleic acid genome, a protein unit or covering called capsid, and a lipid layer.

The nucleic acid genome consists of the DNA and the RNA, both of which stores the genetic information. When a virus enters a host’s body, it reprograms the host based on the genetic information stored in this genome molecule.

The genomes are protectively placed inside a capsule called protein shells called capsid. The shapes of a viral capsid may be helical (like tobacco mosaic virus) or icosahedral (like polio virus). Many polypeptides unite to form the protomers or the capsomers of the capsid.

When a virus is covered by a lipid layer it gains an envelope-like structure.

When a virus is complete with all these essential structures, it is called as virion.  

Pili are microfilamentous structures present in bacteria.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

the glands which are associated with each description is given below: