The Nurse Is Assessing an Older Adult's Functional Ability

The nurse is assessing an older adult's functional ability.Which definition correctly describes one's functional ability? Functional ability:

A) is the measure of the expected changes of aging that one is experiencing.
B) refers to the individual's motivation to live independently.
C) refers to the level of cognition present in an older person.
D) refers to one's ability to perform activities necessary to live in modern society.