A train runs once a week from Delhi to Mumbai and back. It started from Delhi at 9 PM on 16th May, and returned after completing the to and fro journey in a total of 53 hours. What was the date and time when the train returned to Delhi after its journey?
a)18th May, 1 PM
b)18th May, 1 AM
c)19th May, 9 PM
d)19th May, 2 PM