Introduction:
Islamic architecture in India is known for its grandeur and intricate designs. It is a blend of Persian, Turkish, and indigenous Indian architectural styles. Masonry, the art of building structures using individual units laid and bound together, is a prominent feature of Islamic architecture in India.

Explanation:
The correct answer to the question is option 'B' - Dressed stone. Dressed stone refers to stones that have been shaped and finished to fit together smoothly. This technique was extensively used in the construction of Islamic architectural marvels in India.

Reasons for the correct answer:
1. Strength and durability: Dressed stone provides strength and durability to the structures. The stones are carefully shaped and polished, ensuring a tight fit and reducing the chances of structural damage over time.

2. Smooth finish: Dressed stones have a smooth finish, which enhances the aesthetic appeal of the architecture. The intricate carvings and designs on the stones stand out and create a visually pleasing effect.

3. Architectural precision: The use of dressed stones allows for precise construction. The stones can be cut into various shapes and sizes to fit specific architectural requirements. This precision is crucial for the intricate patterns and designs seen in Islamic architecture.

4. Consistency: Dressed stones offer consistency in terms of size and shape. This uniformity is important for maintaining symmetry and balance in the overall design of the structures.

5. Adaptability: Dressed stones can be easily adapted to different architectural styles and can be used in various structural elements such as domes, arches, and minarets. This versatility allows architects to create unique and diverse designs.

6. Historical significance: The extensive use of dressed stone in Islamic architecture in India reflects the influence of Persian and Turkish architectural styles. It showcases the mastery of craftsmen and the cultural exchange that took place during that era.

Conclusion:
Islamic architecture in India is characterized by the use of dressed stone in its construction. This technique provides strength, durability, precision, and aesthetic appeal to the structures. The extensive use of dressed stone in Islamic architecture is a testament to the architectural brilliance and cultural amalgamation of the time.