Final answer:
The underlying theme in The Importance of Being Earnest is that upper class society shortchanges reality when it only judges things by appearance.
Step-by-step explanation:
The underlying theme in The Importance of Being Earnest can be best viewed as D. Upper class society shortchanges reality when it only judges things by appearance. The play satirizes the upper class society of England during that time, poking fun at their superficiality and obsession with appearances. It portrays a world where people are more concerned with maintaining a facade of respectability rather than facing the truth.