The speed of boat in still water on Saturday was 21 km/hr. and that on Sunday was $$28\dfrac{4}{7}\%$$ more than that on Saturday, if the time taken by boat to travel upstream on Saturday is $$2\dfrac{1}{2}$$ times the time taken to travel downstream on Sunday, then find the time taken by the boat to cover a distance of 125 km upstream on Saturday?

A

6 hrs 45 min

B

2 hrs 45 min

C

4 hrs 30 min

D

6 hrs 15 min