Which instrument is commonly used to provide a magnified view of small structures within the body?

The endoscope is the correct choice as it is specifically designed to provide a magnified view of internal structures in the body. This instrument consists of a flexible tube with a light source and a camera attached, allowing veterinary professionals to visualize areas like the gastrointestinal tract or respiratory system. The magnification helps in identifying abnormalities, diagnosing conditions, and even allowing for certain therapeutic interventions.

In contrast, a centrifuge is used to separate components of a mixture by spinning them at high speeds and does not provide visual magnification. A stethoscope is an instrument for auscultation, allowing the practitioner to listen to internal sounds, such as the heartbeat or lung sounds, but it does not magnify images. A reflector typically refers to a device or surface that reflects light or images, which is not relevant for visualizing internal structures.