Set MC value to false in a Side-by-Side question

Hello all,

At the moment I'm struggling with a Side-by-Side question. In the first column I have two subcolumns where a name and emailaddress can be keyed in. In the second column I have a Multiple Choice option for Yes or No. This works so far.

Now I want to retake the response and want to set all options the second column to 'False' (= empty) in stead of displaying the selected choise of the previous response. In the screenshot below it's the column 'Send e-mail?' should all be empty. Or the column 'No' should be selected by default.
!
How can this be done? What Javascript should I use?

I've tried this with:
this.setChoiceValue(1, 1, false);
but this did not work.

Thanks in advance