Interference pattern is absorbed at ' P ' due to superimposition of two rays coming out from a source ' S ' as shown in the figure . The value of ' l ' for which maxima is obtained at ' P ' is : (R is perfect reflecting surface)

Question

$(a)\;l=\large\frac{2 n \lambda}{\sqrt{3}-1}\qquad(b)\;l=\large\frac{(2 n-1) \lambda}{2(\sqrt{3}-1)}\qquad(c)\;l=\large\frac{(2 n-1) \lambda \sqrt{3}}{4(2-\sqrt{3}}\qquad(d)\;l=\large\frac{(2 n-1) \lambda}{\sqrt{3}-1}$