Final answer:
The finest resolution for studying the internal ultrastructure of cells can be achieved using a transmission electron microscope. Electron microscopes use a beam of electrons instead of light, allowing for higher magnification and resolving power.
Step-by-step explanation:
The finest resolution for studying the internal ultrastructure of cells can be achieved using a transmission electron microscope. Electron microscopes use a beam of electrons instead of light, allowing for higher magnification and resolving power. They can reveal internal structures that cannot be viewed with light microscopes. Scanning electron microscopes, on the other hand, are useful for visualizing three-dimensional external shapes at high magnification.