man mount, the
defaults option is filesystem-independent.
FILESYSTEM INDEPENDENT MOUNT OPTIONS
Some of these options are only useful when they appear in the /etc/fstab file.
Some of these options could be enabled or disabled by default in the system kernel. To check the current setting see the options in /proc/mounts.
The following options apply to any filesystem that is being mounted (but not every filesystem actually honors them - e.g., the sync option today has effect only for ext2, ext3, fat, vfat and ufs):
Use default options: rw, suid, dev, exec, auto, nouser, and async.