Allow to check only one checkbox in test inside while

I have a while loop where I get data from database:

<div class="full_qst">
    <div class="drvr"> <?php echo $driver; ?> </div><span class="divider">|</span>
    <div class="sbd_drvr"> <?php echo $subdriver; ?> </div><span class="divider">|</span>
    <div class="qst"> <?php echo $skill; ?> </div>

    <div class="mrk">
        <label class="choice" for="q1_a" >
        <input id="q" name="q1_a[]" type="checkbox" value="<?php echo $low ?>"   />
        1</label>
        <label class="choice" for="q1_a" >
        <input id="q" name="q1_a[]" type="checkbox" value="<?php echo $middle ?>"    />
        2</label> 
        <label class="choice" for="q1_a" >
        <input id="q" name="q1_a[]" type="checkbox" value="<?php echo $good ?>"   />
        3</label>   
        <label class="choice" for="q1_a" >
        <input id="q" name="q1_a[]" type="checkbox" value="<?php echo $vrgood ?>"    />
        4</label>
    </div>
</div>

I get around 15 records. What I want is to allow user check checkbox for each line separately and allow them check only on box on same line. So instead of this:

I want to get this:

I tried to implement this:

$('.mrk input#q').on('change', function() { 
    if($(this).is(':checked')){
        $(':checkbox[name="'  + $(this).prop('name') + '"]').not($(this)).prop('checked',false);
    }
});

But it deselects previous box on upper line and allow me to choose only one checkbox in whole page. Is there a way to solve it?