Which was the last dynasty to rule Ladakh before it became a part of Indian Union?

The correct answer is D. Dogra.

The Dogra dynasty was a Hindu Rajput dynasty that ruled over the princely state of Jammu and Kashmir from the 18th century to 1947. The Dogra rulers were originally from the Jammu region of present-day India. In the 18th century, they conquered Ladakh and other parts of the Kashmir region. The Dogra rulers were known for their military prowess and their patronage of the arts. They built many temples, palaces, and forts in Ladakh. The Dogra dynasty came to an end in 1947, when the princely state of Jammu and Kashmir acceded to India.

The other options are incorrect.

• Option A is incorrect. The Namgyal dynasty was a Tibetan Buddhist dynasty that ruled over Ladakh from the 14th century to the 18th century.
• Option B is incorrect. The Sikh Empire was a Sikh empire that ruled over the Punjab region of India from the 18th century to the 19th century.
• Option C is incorrect. The Afghans ruled over Ladakh from the 16th century to the 17th century.