Which of the Following Preservation Tactics Would Have the Greatest

Which of the following preservation tactics would have the greatest impact on saving the largest number of species?

A) preserve a large tract of land that contains source populations of keystone species
B) preserve several small tracts of land that contain source populations of keystone species
C) preserve a large tract of land that contains sink populations of keystone species
D) preserve a large tract of land that contains source populations of flagship species
E) preserve multiple small tracts of land that each contain source populations of keystone species