[单选题]13.异常验证时结果出现小数时按照（ ）的原则进行修约，最终结果保留整数。
A.四舍五入
B.四舍六入五成双
C.不进行修约

[A] Some archaeological sites have always been easily observable—for example, the Parthenon in Athens, Greece; the pyramids of Giza in Egypt; and the megaliths of Stonehenge in southern England. But these sites are exceptions to the norm .Most archaeological sites have been located by means of careful searching, while many others have been discovered by accident. Olduvai Gorge, fell into its deep valley in 1911.Thousands of Aztec artifacts came to light during the digging of the Mexico City subway in the 1970s.
[B] In another case, American archaeologists Rene million and George Cowgill spent years systematically mapping the entire city of Teotihuacan in the valley of Mexico near what is now Mexico City .at its peak around AD 600, this city was one of the largest human settlements in the word. The researchers mapped not only the city’s vast and ornate ceremonial areas, but also hundreds of simpler apartment complexes where common people lived.
[C] How