How to add multichoice field as radiobutton in Sharepoint 2007 survey?

Hi All,

I  created a survey in sharepoint2007 programatically.Could you please help me to add multi-choice answer fields of type Radiobutton to it?

I tried this

SurveyList.Fields.Add(strQuestion,SPFieldType.MultiChoice,true,false,strQuestions);

But it created a checkbox.

Looking forward to your reply

Celesta