What's the difference between 'practicality' and 'practice'?

[black eyes]

Business English Lesson, Advanced Level

ESL/EFL Test #46 "At the Office (2)", question 4

The ......... of staff doing physical exercises before the start of the day is well established in Japanese companies.

(a) practical
(b) practicality
(c) practice
(d) practically

Business English Lesson, Advanced Level

ESL/EFL Test #46 "At the Office (2)", answer 4

The practice of staff doing physical exercises before the start of the day is well established in Japanese companies.

Correct answer: (c) practice

Your answer was: incorrect
The practicality of staff doing physical exercises before the start of the day is well established in Japanese companies.
_________________________

why can't I use practicality in this sentence?

black eyes

[Mister Micawber]

.
It is difficult to 'establish' the 'practicality' of many things-- in fact, in terms of time commitment and logistics, many Japanese companies have abandoned this practice in recent years on those very grounds.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mister Micawber