Which Definition Correctly Describes One's Functional Ability

Multiple Choice

Which definition correctly describes one's functional ability?

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