First of all, you use a custom mount point. I personally would avoid mounting under /mnt/ via fstab, because that mount point is used usually for temporarily mounted filesystems.
Those seem to be NTFS partitions and you used that way of mounting from some very old documentation you might have came across … I rather highly recommend you to read this:
Usually the partitions will get mounted on /run/media/yourname/MountName/ and KDE Plasma can also do that from Settings > Removable Storage > Removable Devices
and you can set the option when to get mounted as depicted here:
But if you prefer fstab, then follow that guide i mentioned above. Also, in case of NTFS partitions, while dual booting with Windows, you have to make sure that Windows is fully Shutdown, otherwise, in order to fix it might have to run
sudo ntfsfix /dev/sddX
where sddX is the partition in cause, or boot in Windows and fix it from there …