Option a is right

The image formed by objective lens of compound microscope is real and enlarged, while final image formed by compound microscope is inverted, virtual, enlarged and at a distance D to infinite or from an eye, on same side of eye piece

The image formed by an objective lens of a compound microscope is real and enlarged.

Explanation:
A compound microscope consists of two lenses - the objective lens and the eyepiece lens. The objective lens is responsible for forming the primary magnified image of the specimen. Let's understand why the image formed by the objective lens is real and enlarged.

Real Image:
A real image is formed when the light rays actually converge at a point to form an image. In a compound microscope, the objective lens is designed to collect and converge the light rays coming from the specimen. These converged rays form a real image. This real image is then further magnified by the eyepiece lens to make it visible to the observer.

Enlarged Image:
The objective lens of a compound microscope is designed to provide high magnification. It has a short focal length, which means it can bend the light rays at a greater angle. This bending of light rays results in magnification of the image. The magnification produced by the objective lens is usually in the range of 4x to 100x or more, depending on the numerical aperture of the lens.

Advantages of Real and Enlarged Image:
1. Real image: A real image can be projected onto a screen or further magnified by the eyepiece lens. This allows for detailed examination of the specimen and accurate measurements.
2. Enlarged image: The high magnification provided by the objective lens allows for visualization of fine details and structures that may not be visible to the naked eye. It enables scientists and researchers to study microscopic organisms and structures with precision.

In conclusion, the image formed by the objective lens of a compound microscope is real and enlarged. This characteristic of the objective lens allows for detailed examination and study of microscopic specimens.