<?php //Please do not include the opening PHP tag if you already have one

add_action(
  'FHEE__EE_Admin_Page___load_page_dependencies__after_load__espresso_events__create_new',
  'ee_check_all_primary_reg_questions_on_create_event'
);
function ee_check_all_primary_reg_questions_on_create_event() {
  add_action(
    'AHEE_event_editor_questions_notice',
    'ee_custom_checkboxes_for_primary_question_groups'
  );
}
function ee_custom_checkboxes_for_primary_question_groups() {
  echo '<script>jQuery( document ).ready(function($) {
      $("#espresso_events_Registration_Form_Hooks_Extend_primary_questions_metabox input")
      .prop( "checked", true );
    });</script>';
}