Given that sin 60^o = \(\frac{\sqrt{3}}{2}\) and cos 60^o = \(\frac{1}{2}\), evaluate \(\frac{1 - sin 60^o}{1 + cos 60^o}\)

• A.\(\frac{2 + \sqrt{3}}{3}\)
• B.\(\frac{1 - \sqrt{3}}{3}\)
• C.\(\frac{1 + \sqrt{3}}{3}\)
• D.\(\frac{2 - \sqrt{3}}{3}\)