Cho 

Câu hỏi: Cho $\alpha -\beta =\frac{\mathrm{\pi }}{6}$. Tính giá trị P = $\frac{{\left(\cos \alpha +\cos \beta \right)}^2+{\left(\sin \alpha +\sin \beta \right)}^2}{{\left(\sin \alpha -\cos \beta \right)}^2+{\left(\sin \beta +\cos \alpha \right)}^2}$

A. P = 2 - $\sqrt{3}$

B. P = 2 + $\sqrt{3}$

C. P = 3 + $\sqrt{2}$

D. P = 3 - $\sqrt{2}$