Edit in JSFiddle

(function ($) {
    $('#remove_single').on('click', function () {
        var text_to_remove = $('#languages3').val();

        $("#languages3")
            .find("option[value='" + text_to_remove + "']")
            .remove();

    });
})(jQuery);

<div class="code_example">
    <select name="languages" id="languages3">
        <option value="c">C</option>
        <option value="c++">C++</option>
        <option value="php">PHP</option>
        <option value="perl">PERL</option>
        <option value="ruby">RUBY</option>
        <option value="python">PYTHON</option>
        <option value="go">GO</option>
    </select>
    <input type="button" class="btn btn-danger " id="remove_single" value="Remove" />
</div>