单选题 请阅读下面一段程序: import pandas as pd import numpy as np date_index = pd.date_range(start="2018/08/10", periods=5) date_se = pd.Series(np.arange(5), index=date_index) sorted_se = date_se.sort_index() print(sorted_se.truncate(after='2018-8-11')) 执行上述程序,最终输出的结果为( )