Select the most appropriate option to fill in the blank.
Augmented Reality (AR) continues to develop and become more _________ among a wide range of applications.

Correct option is D

The correct option to fill in the blank is (d) pervasive.
"Pervasive" means spreading widely throughout an area or a group of people, which fits the context of AR becoming more widespread.
Meanings of other options:
· Rare: Not occurring very often.
· Amicable: Having a spirit of friendliness.
· Idealistic: Characterized by idealism; unrealistically aiming for perfection.
· Pervasive: Spreading widely throughout an area or a group of people.