Which instrument is used to visualize small particles?

The microscope is specifically designed to magnify small objects and particles, making it possible to visualize details that are not visible to the naked eye. This instrument utilizes lenses to enhance the size of small specimens, such as cells, bacteria, and other microscopic entities. In veterinary medicine, microscopes play a critical role in examining samples such as blood, urine, and tissue to diagnose various health conditions.

In contrast, the other instruments listed serve different purposes. A telescope is intended for observing distant objects, typically in astronomy, and is not suitable for small particles. A stethoscope is used for listening to internal body sounds, such as heartbeats and lung sounds, rather than visualizing objects. A periscope is designed to observe objects that are not in direct line of sight, usually by using mirrors, but it does not provide magnification needed to see small details. The unique function of the microscope in visualizing small particles makes it the correct choice in this context.