Answer: A
\[ (\sqrt{5} - \sqrt{3})(\sqrt{5} + \sqrt{3}) = 5 - 3 = 2 \] \[ \therefore\ a(\sqrt{5} + \sqrt{3}) = 2 \] Or, \[ \sqrt{5} + \sqrt{3} = \frac{2}{a} \]
\[ (\sqrt{5} - \sqrt{3})(\sqrt{5} + \sqrt{3}) = 5 - 3 = 2 \] \[ \therefore\ a(\sqrt{5} + \sqrt{3}) = 2 \] Or, \[ \sqrt{5} + \sqrt{3} = \frac{2}{a} \]