'Brihat Samhita', 'Brihat Jataka' and 'Panchasiddhantika' are notable works of:

"Brihat Samhita", "Brihat Jataka" and "Panchasiddhantika" are the notable works of Varahamihira, the famous astronomer, mathematician and astrologer of the 6th century CE.

About Varahamihira:

• He lived in the 6th century CE (died about 587 CE), and is associated with Ujjain, a major centre of astronomy.
• According to tradition, he was one of the "Navaratnas" (nine gems) at the court of a king Vikramaditya.
• He was a scholar of astronomy, mathematics, astrology, and many other subjects.

His major works:

"Panchasiddhantika" ("Five Treatises"): a summary of five earlier astronomical systems (siddhantas): the Surya, Romaka, Paulisha, Vasishtha and Paitamaha siddhantas. It shows the influence of Greek and Roman astronomy.

"Brihat Samhita": an encyclopaedic work covering astronomy, astrology, planetary movements, eclipses, rainfall, clouds, architecture, the making of images and temples, the qualities of precious stones, perfumes, agriculture, the signs of animals and humans, and many other subjects.

"Brihat Jataka": a major work on horoscopic astrology (predicting the future from the positions of planets at birth).

"Laghu Jataka": a shorter work on astrology.

Contributions:

• He described the method of making a "water clock" and other instruments.
• He made contributions to trigonometry and combinatorics.
• He wrote about the possibility of finding underground water from the presence of certain plants, ant-hills and soil types.
• He noted that the Earth is round and attracted to a central force.

Other ancient Indian scientists:

• "Aryabhata" (born 476 CE): "Aryabhatiya"; explained the rotation of the Earth.
• "Brahmagupta" (7th century): "Brahmasphutasiddhanta"; rules for zero and negative numbers.

Why not the other options?

• ✗Aryabhata wrote the Aryabhatiya.
• ✗Brahmagupta wrote the Brahmasphutasiddhanta.
• ✗Bhaskaracharya was a later (12th-century) mathematician.