The answer is letter C. The distribution of oak trees in an
area.
Population Ecologist would often measure the number
distribution and density of the area. Trees are often measured by plots or by
hectares. This is to know how many trees are situated in that
area.
Convection is the heat transfer used in this transfer.
Stable elements are those which have atleast one isotope with no tendency to "decay", i.e., change into anotherelement.
