This option is found under the same screen as change resolution under ‘Apply the following settings’. There, choose the best resolution available on display and choose the best refresh rate of your monitor.

Choose Change resolution option under the Display. Now that you are done changing the 3D settings, it’s time to make some fundamental changes. Once done, click on the Apply button to make the changes. For this, go to Configure Surround, PhysX option in the left-hand side pane and select your NVIDIA card under the processor located below PhysX settings.