Final answer:
Laminar flow is the state of fluid flow where there is no mixing of layers, making this the correct answer for a system with no blood layer mixing or sounds from vessels.
Step-by-step explanation:
The type of flow where there is no mixing of blood layers or sounds from vessels is known as laminar flow. In laminar flow, fluid moves in parallel layers, with no disruption between them. Viscosity plays a role in this type of flow by causing drag between the layers and with any fixed surfaces they come in contact with. On the other hand, turbulent flow is characterized by the mixing of layers, leading to greater interaction, heating, and resistance within the fluid. This kind of flow can occur in the presence of obstructions within the vessel or at high fluid speeds. Therefore, the correct answer to the student's question is C. laminar.