Kendo MVVM DropDownList - Set Selected Item

No one on stackoverflow.com can answer this, and I can’t find it myself. GQ has rarely failed me before. Can anyone help?

To wit:

I have the following html for a Kendo MVVM DropDownList:

            <select id="responseTypeDDL"
                data-role="dropdownlist"
                data-text-field="SystemResponseTypeCode"
                data-value-field="SystemResponseTypeId"
                data-bind="source: responseTypes">
            </select>

This is my view model:

    SC.ViewModels.Reference.ResponseTypeDataSource.read(); // successfully reads data

    var responseTypeDDL = kendo.observable({
        responseTypes: SC.ViewModels.Reference.ResponseTypeDataSource
    });

    kendo.bind($("#responseTypeDDL"), responseTypeDDL);

The ResponseTypeDataSource.read() method returns a list of “XML” and “JSON”, and these are the values that get added to the dropdown. This is the SystemResponseTypeCode field. I also read another data item from the database and check its response type. Let’s say it is “JSON”. How do I set the drop down to have “JSON” selected?