Explanation:

Correct option:3

Solution:

 The man rows at 10 km/h in still water.

 The river current flows at 4.5 km/h.

 Speed downstream (10 + 4.5) = 14.5 km/h.

 Speed upstream (10 - 4.5) = 5.5 km/h.

 Let the distance to the place be "D" km.

 Time downstream = D/14.5 hours.

 Time upstream = D/5.5 hours.

 Total round trip time = 2 hours.

The equation for time based on distance is:

D/14.5 +D/5.5=2
D=7.975=7.98 (rounded off to two decimal places)