Historical documents have revealed that among the Timucua, a Native American people of Florida, the best from the hunt or the harvest was given to families of high social status, even in times of economic stress. Archaeological research suggests a similar relationship between social status and diet in the Dallas communities of eastern Tennessee, prehistoric Native American groups with a social organization and economy similar to that of the Timucua. The first real clue came when archaeologists discovered that skeletons of higher-status individuals tended to be several centimeters taller than those of people of lower states.
In the largest Dallas communities, some individuals were buried in the earthen mounds that served as sub-structures for buildings important to civic and religious affairs. These burials included quantities of finely carried items made of nonlocal material, denoting the high political standing of those interred. Burials of lower-status individuals contained primarily utilitarian items such as cooking vessels and chipped stone tools and are located in more remote sections of the settlements. The burials actually formed a pattern, the tallest skeletons being found in the mounds, and the heights declining as burials became more distant from the mounds. While it is possible that taller people were simply more successful in achieving high social standing, it is more likely that a number of stresses, including those resulting from a relatively poor diet, which could affect stature, were common among the lower-status groups. Excavations indicate that where food categories made up the bulk of the population's diet: agricultural crops cultivated in the fertile alluvial soils where the communities were located, game, and wild edible plants, primarily nuts. Information about dietary variation among community members is derived by analyzing trace elements in human bone. Higher than normal levels of manganese, strontium, and vanadium probably indicate a less nutritious diet heavily dependent on edible plants. Very low concentrations of vanadium, which is scarce in meats and somewhat lower in nuts than in other plant resources, are good evidence of meat consumption and thus a better balanced-diet. As expected, vanadium was found in considerably greater quantities in skeletons in the burials of lower-status groups.
In highlight text, the author of the passage raises the possibility that taller people achieved greater success most probably in order to

while前面说了长得高的人埋葬的地位高,长得矮的埋葬地位低,while引出一个映对前面发现的可能:长得高的人容易获得高的地位,while逗号后面半句说,也有可能低阶级人的身高是被他们的poor diet影响的,也就是提出了另一个解释。简言之,while处是第一个解释,说长得高的人容易获得高的社会地位,逗号后面是第二个解释,但也有可能低阶级的人本身不矮的,是因为面对很多压力,包括伙食差,影响了他们的身高发音,与第一个解释的翻过了的,所以while是用来引出第二个反对自己的解释。
C选项在,objection就是第二个解释,argument是指第一个解释

