Change selected radio

HTML

<fieldset>
<legend>Some radios</legend>
<label><input type="radio" name="radRadio" value="A"> Value A </label>
<label><input type="radio" name="radRadio" value="B"> Value B </label>
<label><input type="radio" name="radRadio" value="C" checked="checked"> Value C </label>
<label><input type="radio" name="radRadio" value="D"> Value D </label>
</fieldset>
<button>Change value</button>

CSS

label { display:block;}

JavaScript

$(document).ready(function(){
    
    $("button").click(function(){
    
    $("input[value='D']").attr("checked","checked");
    });
    
    console.log( $("input[value='tt']")        );
    console.log( $("input[value='tt']")[0]     );
    console.log( $("input[value='tt']").attr("checked","checked")        );
    
});