Option b is the correct answer. Hemachandra (c. 1088 - c. 1172/1173 CE) was a versatile 12th-century Indian Jain scholar, poet, mathematician, philosopher, and grammarian. Renowned as "kalikālasarvajña," he authored works on politics, history, and Jainism. Born as Changadeva, he became a key advisor to King Kumarapala and contributed to Sanskrit literature. His notable works include "Yogaśāstra" on Jain path, "Siddha-Hema-Śabdanuśāśana" grammar, "Arhanniti" on politics, "Trisastiśalākāpurusacharitra" on Jain figures, "Chandonushasana" on prosody, and early description of Fibonacci sequence.