This will get the index of the selected option on change:
$('select').change(function(){_x000D_
console.log($('option:selected',this).index()); _x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<select name="CCards">_x000D_
<option value="0">Select Saved Payment Method:</option>_x000D_
<option value="1846">test xxxx1234</option>_x000D_
<option value="1962">test2 xxxx3456</option>_x000D_
</select>
_x000D_