Checkbox insert 1 or 0 into SQL database

I am setting up a system that has many answers from a question. Therefore the user can click a button to dynamically add answers. I want the user to be able to tick a checkbox next to the answers which are correct and then insert this into the database (1 being correct).

Here is what I have:

HTML:

<div id="answers">
 <label class="answer">
  Answer:
   <input type="text" name="ab_name[]" value=""/>
    Correct?
   <input type="checkbox" name="ab_correct[]" value="0">
 </label>
</div>

PHP

$ab_name = $_POST['ab_name'];
$ab_correct = $_POST['ab_correct'];

$sql = "INSERT INTO answers_bank (`ab_name`, `ab_correct` ) VALUES (:ab_name, :ab_correct )";
$stmt = $db->prepare($sql);

foreach ($_POST['ab_name'] as $ab_name) {
$stmt->bindValue(':ab_name', $ab_name);
$stmt->bindValue(':ab_correct', $ab_correct);
$stmt->execute();
}

Like this:

The SQL inserts the ab_name but the ab_correct is ALWAYS set to 1 if it is ticked or unticked. Any guidance on this please?