Option b is the correct answer. Vikram Samvat, also known as Bikram Sambat, began around 57 B.C. The calendar system, used in Nepal and some states of India, is approximately 57 years ahead of the Gregorian Calendar. The Samvat is named after the legendary king Vikramaditya, though historical records show its use only from the 9th century. The calendar's origin is linked to the expulsion of the Sakas from Ujjain by King Vikramaditya, commemorated by the start of the Vikrama era. It is a lunisolar calendar based on the moon's movement with 354 days in a year. It has 12 months, each with two phases - Shukla paksha (new moon to full moon) and Krishna paksha (full moon to new moon). It begins after Diwali in Gujarat and Maharashtra. Important Tips Types of calendars in India: Saka Samvat: An ancient Indian calendar used alongside Vikram Samvat. Begins in 78 A.D. marking Saka era and King Shalivahana's victory. Used in some regions, mainly for religious purposes. Hijri Calendar: Islamic lunar calendar with 12 months and 354/355 days. Starts in AD 622 during Prophet Muhammad's migration (Hijra) from Mecca to Medina. Determines Islamic holidays, fasting, and pilgrimage timings. 12 months like Muharram, Safar, etc. Gregorian Calendar: Introduced in 1582 by Pope Gregory XIII as a correction to the Julian Calendar. Most widely used worldwide. 365/366 days in a year, adjusting leap years. Months like January, February, etc.