An individual covered under a disability income policy may be eligible for a partial disability benefit if

The correct answer to this question is if the individual can no longer perform at their full physical capacity.

When an individual becomes permanently disabled it means that they have lost the ability to ever work again. Someone who qualifies for partial disability has the ability to still work, but not at full capacity. An example of this may be a person who loses a limb. They are still able to work, but not at the capacity that they could before the injury.