下面程序段计算学生的外语附加分：外语6级（lang6）为 ”优秀” 加15分，”通过” 加10分；外语4级（lang4）为 ”优秀” 加8分，”通过” 加4分，外语附加分只能计一次最高的分数。下面 能正确计算。A:If lang6 = “优秀” Then langf = 15ElseIf lang6 = “合格” Then langf = 10ElseIf lang4 = “优秀” Then langf = 8ElseIf lang4 = “合格” Then langf = 4Else langf = 0EndIf B:If lang4 = “合格” Then langf = 4ElseIf lang4 = “优秀” Then langf = 8ElseIf lang6 = “合格” Then langf = 10ElseIf lang6 = “优秀” Then langf = 15Else langf = 0EndIf C:If lang6 = “优秀” Then langf = 15If lang6 = “合格” Then langf = 10If lang4 = “优秀” Then langf = 8If lang4 = “合格” Then langf = 4 langf = 0 D:If lang4 = “合格” Then langf = 4If lang4 = “优秀” Then langf = 8If lang6 = “合格” Then langf = 10If lang6 = “优秀” Then langf = 15 Else langf = 0 E:If lang6 = “优秀” Then langf = 15If lang6 = “合格” Then langf = 10If lang4 = “优秀” Then langf = 8If lang4 = “合格” Then langf = 4 Else langf = 0 答案: If lang6 = “优秀” Then langf = 15ElseIf lang6 = “合格” Then langf = 10ElseIf lang4 = “优秀” Then langf = 8ElseIf lang4 = “合格” Then langf = 4Else langf = 0EndIf