Students Studying a Population of Salamanders in a Vernal Pool

Students studying a population of salamanders in a vernal pool mark each salamander caught as it's entering the pool. During the first spring migration to the pool, the students mark 200 salamanders. The following year, they again capture 200 salamanders. Of these, 20 were from the previous year. Students use this information to calculate that they captured ________ of the total population and that the total salamander population in their pool is about ________.

A) 20%; 200
B) 10%; 2000
C) 20%; 2000
D) 10%; 200