Explanation:

- The word pair "Lazy : Hard-working" demonstrates a relationship of opposites. A lazy person typically avoids effort, while a hard-working person puts in effort.

- Similarly, for "Wealthy : ?", you need a word that is the opposite of wealthy.

- Option 1, Money, is associated with wealth but not an opposite.

- Option 2, Unhappy, is related to emotions, not wealth.

- Option 3, Rich, is a synonym, not an opposite.

- Option 4, Penniless, is the opposite of wealthy, referring to lack of money.

Therefore, the correct answer is:

- Option 4: Penniless