Directions: Read the below passage and answer the questions that follow:
Boat A is going ___(1) __ at a speed of ___(2) __ km/hr from point A in a stream of speed ___(3) __ km/hr thus the speed of boat in still water is ___(4) __ km/hr. After travelling a distance of ___(5) __ in ___(6)__ hours it reaches point B it turns around and reaches the starting point in ___(7) __ hours. When the boat A leaves point A, boat B at point B starts travelling ___(8) __.
(1) is upstream (4) and (3) is 28 and 4 respectively. (5) is 630 km and speed of boat B in still water is (4) less than by 2 with (8) being at same time. After how many hours do both the boats meet?

Options

A. `11 2/3` hours
B. `17 1/3` hours
C. `8 3/4` hours
D. `9 2/3` hours