[单项选择题] 单击一次命令按钮之后，在对话框中输入12，2，34，23，窗体中的输出结果为

[单项选择题] 单击一次命令按钮之后，在对话框中输入12，2，34，23，窗体中的输出结果为______ 。 Private Sub Command1_ Click ()Dim a(4) As IntegerFor i = 1 To 4 a (i) = Val (InputBox (“请输入元素”))Next iplus a(1), a(2), a(3) End Sub Sub plus(first As Integer, second As Integer, third As Integer, Optional forth)n = first + second + thirdIf Not IsMissing (forth) Then n = n + forthEnd If Print n End Sub

A．14

B．71

C．48

D．37

C