Register.php

        // account status
        $form->add(array(
            'name' => 'enabled',
            'type' => 'Zend\Form\Element\Select',
            'options' => array(

                'value_options' => array(

                    0 => 'Disabled',
                    1 => 'Enabled'
                )
            ),

            'attributes' => array(

                'value' => 1
            )
        ));