Which of the Following Is an Important Problem in Predicting

Multiple Choice

Which of the following is an important problem in predicting future extinction rates?

A) Scientists often do not know all of the details of the ecological roles of species.
B) Most of the world's species have already been identified.
C) It is difficult to work out how many individuals are needed for a population to be viable.
D) Scientists have no information about extinctions prior to having written human records.
E) Mathematical models cannot be used to make these predictions even when detailed data are available for species because the models are so complex.