Final answer:
The condenser lens is the part of a microscope responsible for gathering and focusing light to illuminate the specimen, crucial for observing details at high magnifications. option a is answer
Step-by-step explanation:
In microscopy, the condenser lens is responsible for gathering diffuse rays from the microscope light source and illuminating the specimen with a small cone of bright light. The condenser lens, which is located just below the stage of the microscope, helps to focus light through the specimen.
This is particularly important at higher magnifications where details require more light for visibility. Adjustments to the illumination can be achieved by varying the light's intensity, moving the condenser lens, or by using the iris diaphragm. Dark field and laser light illumination are examples of more specialized applications using condenser systems. option a is answer