Check a radio button from data saved in localstorage in a specific form, with a specific name and value

I have the following html:

<form class="questionnaire" name="X">
        <table>
            <tr>
                <td>1. text</td>
                <td><label><input type="radio" name="q1" value="B" >Yes     </label><label><input type="radio" name="q1" value="C" >No </label></td>
            </tr>
            <tr>
                <td>2. text</td>
                <td><label><input type="radio" name="q2" value="B" >Yes     </label><label><input type="radio" name="q2" value="C" >No </label></td>
            </tr>

I have saved in localstorage the form name (‘X’), the input type (radio), the input name (‘q1’), and the input value (‘B’) for example, and I am trying to ensure that on a page refresh the form is repopulated so the user doesn’t lose their input. So far I have the following code to to set the radio buttons to checked but I keep getting a ‘is not a function’ error:

function populateFormInput(key, val) {
    var keyParts = key.split('|');
    var inputForm = keyParts[0];
    var inputType = keyParts[1];
    var inputName = keyParts[2];

    if (inputType === 'radio') {
        $('form[name="inputForm"] input[name="inputName"][value="val"]').prop('checked', true);
    }
}

I can’t edit much of the html, though I could give the form an ID if that would help things?

Thanks in advance!

$('form[name="' + form_name + '"] input[name="' + field_name + '"][value="' + field_value + '"]').prop('checked', true);