Find the sum of the expression $$\frac{1}{\sqrt{1}+\sqrt{2}} + \frac{1}{\sqrt{2}+\sqrt{3}} + \frac{1}{\sqrt{3}+\sqrt{4}} + \dots + \frac{1}{\sqrt{80}+\sqrt{81}}$$

Rationalize the general $n^{\text{th}}$ term by multiplying the numerator and denominator by its conjugate $(\sqrt{n+1} - \sqrt{n})$:

Applying this identity to each term in the series gives a telescoping sum:

All intermediate terms cancel out:

Hence, the correct option is 8 (Option B).