Why does the author include the comment "though they were fed the same diets"? A. To show why rats living in impoverished environments need less food than those living in enriched environments B. To eliminate the possibility that differences in diet were responsibly for observed differences in brain weight C. To emphasize the point that rats were fed only the amount of food needed to keep them alive D. To suggest that rats fed the same diet have smaller brains than those fed a varied food