Default Dynamic Dropdown value: how to set??

Given the code below, how do I set the default selected value?? Having trouble finding a clear answer anywhere

add_filter( 'wpcf7_form_tag', 'customDropdownFunction', 10, 2); //add a new form tag function

function customDropdownFunction($options){
    if ( $options['name'] != 'customDropdown' ) { //check if the name of your tag is the same as step 2 — if its the same, run the function, if not then ignore
        return $options;
    }

    global $wpdb; //use WordPress database connection or replace with your own for external / not in WP database table

    //$data = $wpdb->get_results( "SELECT * FROM database_table" ); //select frmom custom database table inside of WP database or replace with whatever you need

    $data = array(
        '1' => 'one',
        '2' => 'two',
        '3' => 'three'
    );

    foreach($data as $value=>$label){
        $options['raw_values'][] = $value . '|' . $label; //using pipes to put the value before the pipe and the label after by picking up the ID and LabelName fields from the database
    }

    $pipes = new WPCF7_Pipes($options['raw_values']); //use the WPCF7_Pipes class

    $options['values'] = $pipes->collect_befores(); //get value vefore pipe

    $options['pipes'] = $pipes;

    $options['labels'] = $pipes->collect_afters(); //get label after pipe

    return $options;

}