Can't display select fields

Hi,

i make a custom plugin to submit post type via front end, but i have a problem with all select fields, this is my code :

$values = rwmb_meta( 'scadenza_prodotti_rinnovabili' );
foreach ( $values as $value ) {
    echo $value;
}

this is my meta

array(
    'id'          => 'scadenza_prodotti_rinnovabili',
    'name'        => 'Scadenza',
    'type'        => 'select',
    'placeholder' => 'Seleziona',
    'options'     => array(
        'Mensile'     => 'Mensile',
        'Trimestrale' => 'Trimestrale',
        'Semestrale'  => 'Semestrale',
        'Annuale'     => 'Annuale',
    ),
    'visible'     => array(
        'when'     => array(
            array( 'domanda_prodotto_rinnovabile', '=', '1' ),
        ),
        'relation' => 'or',
    ),
),

also i have another select with some conditional statement but i cant display in my form

Thanks.