Retrieve option value for a given blog id based on name of option.

If the option does not exist or does not have a value, then the return value
will be false. This is useful to check whether you need to install an option
and is commonly used during installation of plugin options and to test
whether upgrading is required.

If the option was serialized then it will be unserialized when it is returned.

function get_blog_option( $id, $option, $default = false ) {
	$id = (int) $id;

	if ( empty( $id ) ) {
		$id = get_current_blog_id();
	}

	if ( get_current_blog_id() == $id ) {
		return get_option( $option, $default );
	}

	switch_to_blog( $id );
	$value = get_option( $option, $default );
	restore_current_blog();

	/**
	 * Filters a blog option value.
	 *
	 * The dynamic portion of the hook name, `$option`, refers to the blog option name.
	 *
	 * @since 3.5.0
	 *
	 * @param string  $value The option value.
	 * @param int     $id    Blog ID.
	 */
	return apply_filters( "blog_option_{$option}", $value, $id );
}