Explanation:

- Telling someone something you admire about them can be a random act of kindness. It's a small gesture but has a big impact.

- It takes almost no effort yet it pays enormous dividends. Compliments are simple and don’t require much energy or planning.

- Effort: Best fits as it implies minimal physical or mental exertion.

- Many people spend their lives wishing others would appreciate them. Everyone likes to feel valued and noticed.

- Expectations are higher from family and friends; however, even compliments from strangers feel good if genuine. We all enjoy positive recognition.