wp select options dropdown for meta box

meta-box-select-dropdown.php

<?php 
/**
 * Add meta box to editor
 * 
 * @strings $id, $title, $callback, $screen, $context, $priority, $args  
 * function's action_added in register cpt 
 */
function vertycal_date_time_meta_box() 
{
    add_meta_box(
        'vertycal_mark_done_meta', 
        __( 'Mark As', 'vertycal' ), 
        'vertycal_mark_done_meta_box_cb', //callback
        'vertycal',                      // post type screen 
        'side',                 
        'low' 
    );
}
 
/**
 * Output the HTML for the metabox.
 */
function vertycal_mark_done_meta_box_cb($post) 
{

    global $post;
    //maybe options
    $opta = __( 'Select Please' );
    $optb = __( 'Pending' );
    $optc = __( 'On Board' );
    $optd = __( 'Fulfilled' );
    
    $vertycal_mark_done = '';
    $vertycal_mark_done = get_post_meta( $post->ID, 'vertycal_mark_done_meta', true );
    ob_start();
    $vtcl_option = array( 
        'vtcl_selects'  => $opta,  
        'vtcl_pending'  => $optb, 
        'vtcl_progress' => $optc,
        'vtcl_complete' => $optd  
    );
        // Output the field  
        printf( '<select id="%1$s" name="%1$s">', 'vertycal_mark_done_meta' );
        
        foreach( $vtcl_option as $key => $value ) 
        {
echo '<option value="' . $key . '"' . selected( $vertycal_mark_done, $key ) . '>' . $value . '</option>';
        } 
        print( '</select>' );
        wp_nonce_field( 'vertycal_mark_done', 'vertycal_mark_done' );
    
    $output = ob_get_clean();
    echo $output;
}