Introduction:
Superconductors are a special class of materials that exhibit zero electrical resistance below a certain critical temperature. They have unique properties that make them highly desirable for various technological applications, including power transmission, energy storage, and medical imaging. Understanding their magnetic behavior is crucial for harnessing their potential.

Diamagnetic Materials:
Diamagnetic materials are those that possess no permanent magnetic moment and are repelled by a magnetic field. When subjected to an external magnetic field, the induced magnetic moment in diamagnetic materials is in the opposite direction to the applied field.

Superconductors and Diamagnetism:
Superconductors are indeed diamagnetic materials. Below their critical temperature, superconductors expel any magnetic field from their interior, a phenomenon known as the Meissner effect. This expulsion of magnetic flux is a consequence of the perfect conductivity and zero resistance exhibited by superconductors. The expelled magnetic field creates a screening current on the surface of the superconductor that generates a magnetic field in the opposite direction, effectively canceling out the applied magnetic field.

Explanation of the Correct Answer:
The correct answer is option 'A' - True. Superconductors are indeed diamagnetic materials. This is a well-known and established fact in the field of materials science and condensed matter physics. The Meissner effect, which is the hallmark of superconductivity, demonstrates the diamagnetic behavior of superconductors.

The diamagnetic property of superconductors has significant implications. It allows for the levitation of superconducting materials in the presence of a magnetic field, known as magnetic levitation or "quantum locking." This phenomenon has practical applications in various fields, such as transportation systems and magnetic bearings.

Conclusion:
In conclusion, superconductors are indeed diamagnetic materials. Their ability to expel magnetic fields from their interior, known as the Meissner effect, is a key characteristic of superconductivity. Understanding and harnessing the diamagnetic behavior of superconductors is essential for their utilization in various technological applications.