CODE EXAMPLE FOR HTML

bootstrap radio button block

<!-- Default radio -->
<div class="form-check">
  <input class="form-check-input" type="radio" name="flexRadioDefault" id="flexRadioDefault1"/>
  <label class="form-check-label" for="flexRadioDefault1"> Default radio </label>
</div>

<!-- Default checked radio -->
<div class="form-check">
  <input class="form-check-input" type="radio" name="flexRadioDefault" id="flexRadioDefault2" checked/>
  <label class="form-check-label" for="flexRadioDefault2"> Default checked radio </label>
</div>