An woman swims downstream 45 km and upstream 25 km taking 5 hours each time; what is the speed of the current?	Choose the correct choice from the following choices.
A) 2	B) 1	C) 3	D) 4	E) 2.1

Rationale: "45 - - - 5 ds = 9 ? - - - - 1 25 - - - - 5 us = 5 ? - - - - 1 s = ? s = ( 9 - 5 ) / 2 = 2 answer : a"
Answer: A