Correct option is C
Ujjain, located in Madhya Pradesh, is referred to as the "Greenwich of India". Historically, the city served as the Prime Meridian of ancient India, with all Indian time calculations being based on its geographical location. The ancient astronomers used Ujjain's longitude as the reference point for time and space calculations, much like Greenwich in England is used today for the global time zone system. Ujjain’s significance in Hindu cosmology and astronomy continues to be acknowledged in historical references and religious texts.
