Radio Button
<input type="radio" id="option_a" name="optionen" value="option_a" />
<label for="option_a">Option A</label>
<input type="radio" id="option_b" name="optionen" value="option_b" />
<label for="option_b">Option B</label>
<input type="radio" id="option_c" name="optionen" value="option_c" />
<label for="option_c">Option C</label>