Atheory in science is
a. a synthesis of well-tested ideas.
b. an agreement between trained investigators.
c. an educated guess.
d. forever true.

It would be (a)

Explanation:

A theory is something that can be proved through rigorous and repeated experimentation, while choice (b) sounds tempting i believe it fails at the fact that it says that a theory is an "agreement", sure an agreement could be reached by while trained scientists but that does not necessarily mean that what the scientists agree upon is rigorously tested and repeatable, and so therefore cannot be assumed

That is what I think

Hope this helps :)  

need to see circuit to get time constant

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min