What is the value of the following expression?

​$$\frac{\sqrt{7} - \sqrt{3}}{\sqrt{7} + \sqrt{3}} + \frac{\sqrt{7} + \sqrt{3}}{\sqrt{7} - \sqrt{3}} + \frac{\sqrt{3} + 1}{\sqrt{3} - 1} + \frac{\sqrt{3} - 1}{\sqrt{3} + 1}$$​​

Correct option is B

Given:

​$$\frac{\sqrt{7} - \sqrt{3}}{\sqrt{7} + \sqrt{3}} + \frac{\sqrt{7} + \sqrt{3}}{\sqrt{7} - \sqrt{3}} + \frac{\sqrt{3} + 1}{\sqrt{3} - 1} + \frac{\sqrt{3} - 1}{\sqrt{3} + 1}$$ 

Formula used:

​$$\begin{aligned}& (A+B)^2=A^2+B^2+2 A B \\& (A-B)^2=A^2+B^2-2 A B \\& (A+B)(A-B)=A^2-B^2\end{aligned}$$ 

Solution:

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