What primary function does a microscope serve in medical diagnostics?

The primary function of a microscope in medical diagnostics is to view objects that are too small for the naked eye. Microscopes allow healthcare professionals to observe cellular structures, microorganisms, and tissue samples at high magnification levels, revealing details that are essential for diagnosis and research. This capability is critical when analyzing samples for conditions such as infections, cancers, and other diseases, as it enables the identification of pathogens or abnormal cells that may not be visible otherwise.

In the context of the options provided, the other functions—like measuring blood pressure, analyzing urine samples, and providing radiation therapy—do not involve the fundamental role of a microscope. They utilize different types of equipment or techniques specific to their functions. Thus, the option about viewing small objects accurately captures the essential contribution of microscopes in medical settings.