Final answer:
To visualize cells, one typically uses a microscope, an instrument that magnifies objects to a scale where cellular structures become visible (option 2). Microscopes can produce micrographs, and special preparation of samples, such as blood smears, allows for detailed observation of cells and their components.
Step-by-step explanation:
To visualize cells, the most effective tool is a microscope. Cells, such as a typical human red blood cell, elude the eye with their minute size of about eight micrometers in diameter. Microscopes magnify these tiny structures to a size where we can observe and study them, producing images known as micrographs. There are different types of microscopes, such as light microscopes which are commonly used to view cell structure and electron microscopes for more detailed images of a cell's interior.
For viewing the cellular components of blood, for instance, one must first spread a very thin layer of blood on a glass slide to create a 'feathered edge'. This preparation can then be analyzed under a microscope either unstained or treated with special stains to enhance the visibility of individual components.
Much of our understanding of cellular biology stems from microscopy. The development of cell theory, which describes cells as the basic unit of life, was significantly aided by the advancements in microscopic technology and techniques.
Hence, the answer is option 2.