The Switch to Extensive Harvesting of Wild Grain, Fishing and Hunting

The switch to extensive harvesting of wild grain, fishing and hunting of smaller game during the Mesolithic appears to have been accompanied by a marked decline in human stature; this would seem to indicate that

A) the decline in stature was due to a poorer diet in the mesolithic compared to the Upper Paleolithic.
B) we have not discovered enough Mesolithic skeletons to properly assess what the average stature of humans was.
C) natural selection no longer favoured greater height because only smaller game were being hunted.
D) even though peoples' health improved in the Mesolithic, stature declined.
E) people were dying before they had attained their full adult stature.