Viral spikes…. A. block attachment between virus and host. B. protrude from the envelope. C. All of the choices are correct. D. are always present on enveloped viruses. E. are derived from host proteins.

Answer: B. Viral spikes protrude from the envelope. Explanation: Viral spikes are glycoprotein structures that protrude from the envelope of some viruses. These spikes play a crucial role in the attachment of the virus to the host cell and subsequent entry into the host cell. The viral envelope is typically derived from the host cell membrane, but the viral spikes are encoded by the virus itself. Therefore, Option E is incorrect. Option A is incorrect because viral spikes facilitate attachment between the virus and host cell. Option C is incorrect because not all viruses have spikes, and not all spikes block attachment. Option D is incorrect because not all enveloped viruses have spikes.