When storing option for current-site (sub-site), we use get_option, however, when we want to have one centralized option (which should apply to all sub-sites, including the primary sub-site), which one is better to be used:
- {get/update}_site_option
- {get/update}_network_option
- {get/set}_site_meta
so, in case the host is not Multi_Site, the function should automatically fallback to current site's option (as get_options does).
