I cannot seem to figure out what the trick on this problem is:

12. In a certain pond, 50 fish were caught, tagged, and
returned to the pond. A few days later, 50 fish were
caught again, of which 2 were found to have been
tagged. If the percent of tagged fish in the second
catch approximates the percent of tagged fish in the
pond, what is the approximate number of fish in the
pond?

(A) 400
(B) 625
(C) 1,250
(D) 2,500
(E) 10,000