You are creating a multiple document interface ( MDI) application by using the .NET Framework 3.5 . You configure the frmParent form to be an MDI parent.You write the following code segment (Line numbers are included for reference only.)<br /> <img src="https://nimg.ppkao.com/2018-08/zhoulian/2018080109350841647.jpg?sign=d6b4e8947f407f1f421f680cef98726b&t=62d445e2" /><br /> You need to associate and display the frmChild form and the frmParent form.  <br /> Which code segment should you add?()<br /> <img src="https://nimg.ppkao.com/2018-08/zhoulian/2018080109352126339.jpg?sign=16e474ec87abd54dad6be64d4a8a6e3c&t=62d445e2" />
A、A
B、B
C、C
D、D