The correct answer is: A. Vastupal and Tejapala.
Vastupal and Tejapala were two brothers who were ministers in the court of the Chaulukya king Kumarapala. They were Jains and were patrons of the Jain faith. They built the famous temple of Mallinath on the Girnar hill in Gujarat, India. The temple is one of the most important Jain temples in the world.
B. Pratishtha King Nag Bhatt II was a Jain king who ruled the Chaulukya dynasty in the 12th century. He was a great patron of the Jain faith and built many Jain temples. However, he did not build the temple of Mallinath on the Girnar hill.
C. Mularaja was a Jain king who ruled the Chaulukya dynasty in the 11th century. He was a great patron of the Jain faith and built many Jain temples. However, he did not build the temple of Mallinath on the Girnar hill.
D. Udayamati was the queen of the Chaulukya king Kumarapala. She was a Jain and was a patron of the Jain faith. However, she did not build the temple of Mallinath on the Girnar hill.