Final answer:
The envelope of a virus is derived from the host's plasma membrane, and it contains lipids and proteins, including glycoproteins from the host cell. The correct answer is option d).
Step-by-step explanation:
The envelope of a virus is derived from the host's membrane structures, specifically the plasma membrane. Enveloped viruses, like the influenza virus and HIV, acquire this membrane through a process where they bud from the host cell, incorporating a portion of the cell's membrane with embedded viral glycoproteins around their capsid.
This viral envelope is composed of a lipid bilayer with associated proteins, with the lipids and any carbohydrates being sourced entirely from the host cell. These glycoproteins play crucial roles in attachment to and penetration of host cells, initiating infection.
Membrane structures like the endoplasmic reticulum and nuclear membrane can also contribute to the formation of the viral envelope in some viruses. The envelope helps the virus in evading the host immune system and is a target for antiviral drugs and immune responses.