What tool is used to see cells more clearly?

The microscope is the correct choice because it is specifically designed to magnify small objects, such as cells, that are not visible to the naked eye. It allows scientists and students to observe the details of cell structure, including organelles and other microscopic features, which are crucial for understanding biology and the functions of living organisms. By using different types of microscopes, such as light microscopes or electron microscopes, one can achieve varying levels of magnification and clarity, making it an essential tool in cellular biology and science education.

In contrast, a thermometer is used to measure temperature, a stethoscope is used to listen to internal sounds in the body, such as heartbeats or lung sounds, and binoculars are designed for seeing distant objects more clearly, making them unsuitable for viewing tiny biological structures like cells.