Vikramaditya, a king of Ujjain, started the Vikrama samvat in 58 BC in commemoration of his victory over

Answer: Option B

Vikramaditya, a king of Ujjain, started Vikrama Samvat era in 58 BCE after defeating the Shakas, and those who believe that he is based on a historical figure place him around the first century BCE. However, this era is identified as "Vikrama Samvat" after the ninth century CE. Other scholars believe that Vikramaditya is a mythical character, since several legends about him are fantastic in nature.