What is the correct combination for estimating population using mark-recapture?
A valid mark–recapture estimate requires information about the first marked sample, the size of a later capture, and how many marked individuals appear in that later capture. It also requires assumptions: marks are retained and recognized, marking does not alter survival or catchability, marked organisms mix into the population, sampling probabilities are comparable, and the population is effectively closed during the study interval. These conditions justify M/N ≈ R/C and hence N ≈ MC/R. The row refers to statements labeled A–E, but those statements are absent from the workbook’s question text and options; only combinations of labels are supplied. Consequently, the biological content of the keyed combination “A, B and D” cannot be verified from this row alone. Interpreting the preserved key requires assuming that A, B, and D correspond to the necessary quantities or assumptions above and that the omitted statements violate them. Scientifically, any combination should be judged by whether it supports representative mixing and an unbiased marked fraction, not merely by its labels. Missing stem data should be restored before the item is used independently.
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 9