Answer:
Option D
Step-by-step explanation:
Diagram is attached.
Capsid protein is a form of structural protein which usually forms part of a complex which later produces protective shell around the nucleic acid in a virus. It is also referred to as coat protein or head protein.
Capsid acts as a distinguishing feature for identifying an integrated viral genome, plasmids and other genetic material of viruses. In fact, viruses are termed as organisms that encode capsid proteins.
Hence, option D is correct