During an ecological study, a population of tilapia fish in a pond was estimated using the mark-recapture method. In the first sample, 60 fish were caught, marked, and released. In the second sample, 80 fish were caught, of which 20 were marked. What is the estimated population size of the tilapia in the pond?

Using the Lincoln-Petersen formula: Population (N) = (first catch × second catch) / recaptured marked individuals = (60 × 80) / 20 = 4800 / 20 = 240. Option A results from adding the two samples (60 + 80 + 20), Option C results from multiplying 80 by 4, and Option D results from a common arithmetic error of dividing by 10 instead of 20.