$form->field(
        name       => 'answers',
        label      => 'Answers:',
        type       => 'checkbox',
        multiple   => 1,
        options    => [['value','displayed1'],['value2','displayed2']],
        add_after_option => "<br>",
        linebreaks => 1,
        cleanopts => 0,
        validate => \&sub_call
    );