In the passage, the author is primarily concerned with

A． Migration between towns stands in direct contrast with the accumulation of population in cities.
B． Parish populations would grow at fairly equal rates, given the fact that those who left a parish in response to life course events were usually replaced.
C． Migration between parishes was a rare enough phenomenon that it was unnecessary to keep records of it in any fashion.
D． Parish populations often chose to remain sedimentary as a result of the homogeneity of the various countryside parishes.
E． Parish populations owed their existence on the whole to the influx of populations due to life course events.

A． analogue
B． conversation
C． epilogue
D． monologue
E． tetralogy