Option a is the correct answer. Upanishadas were translated into Persian during the reign of Shah Jahan. Dara Shikoh, the eldest son of Mughal Emperor Shah Jahan, undertook the translation of Upanishads from Sanskrit to Persian, aiming to make these texts more accessible. In addition, he translated significant religious texts like Yoga Vashishta and Bhagwat Gita, emphasizing philosophical and metaphysical subjects. Dara Shikoh's contributions extended to writings on Sufism and the biographies of Sufi saints, revealing his diverse interests and intellectual pursuits.