I recently installed Ubuntu 16.04.3 on my Thinkpad X1 Carbon 3rd Gen laptop. However, there is no "Natural Scrolling" option for the touch pad. Here is how to fix it.
Use this command to enable Natural Scrolling.
$ gsettings set org.gnome.desktop.peripherals.touchpad natural-scroll true
Here is the mouse settings: there's no natural scrolling option!