Which of the Following Methods Would Provide the Most Legitimate

Multiple Choice

Which of the following methods would provide the most legitimate data on population density?

A) Count the number of nests of a particular species of songbird,and multiply this by two (because there are two parent birds per nest) .
B) Count the number of pine trees in several randomly selected 10-m × 10-m plots,and extrapolate this number to the fraction of the study area that these plots represent.
C) Calculate the difference between all of the immigrants and emigrants to see if the population is growing or shrinking.
D) Add the number of births and subtract the number of individuals who die to see if the population's density is increasing or decreasing.