ANS:D - None of these

All of the characteristics mentioned (corrosiveness, fouling characteristic, and viscosity) are important factors to consider when deciding the route of a fluid in a shell and tube heat exchanger. Each of these factors can impact the performance, efficiency, and maintenance requirements of the heat exchanger.

• Corrosiveness: Corrosive fluids can damage the materials of construction used in the heat exchanger, leading to leaks or equipment failure. Therefore, it's crucial to route corrosive fluids in a way that minimizes their contact with vulnerable components.
• Fouling characteristic: Fouling refers to the accumulation of unwanted deposits on heat transfer surfaces, reducing heat transfer efficiency. The route of a fluid should be chosen to minimize fouling and facilitate cleaning or maintenance as needed.
• Viscosity: Viscous fluids have a higher resistance to flow, which can affect the pressure drop and flow distribution within the heat exchanger. Proper routing of viscous fluids can help optimize flow conditions and ensure efficient heat transfer.