The following statement will insert str into the list box at the proper sorted position ( 按照顺序排列的位置 ) and assign the index of that position to num . Which one of these properties must also have been set to allow the statement to complete the described tasks? num = lstbox.Items.Add(str)
A.
the Sorted property of the list box has been set to Alphabetical.
B.
the Sorted property of the list box has been set to True
C.
the Sorted property of the list box has been set to False.
D.
the Count property of the list box has been set to Sorted.