Consider an experimental setup where three equally spaced and equal-intensity coherent sources of green light (L₁, L₂, and L₃) are placed in a line. Using the phasor method and phase difference $𝛿=\frac{2\pi dsin\theta}{\lambda}$, determine the relative intensity $I/I_0$ of the light at point S.

• A. $\frac{(1+2 \cos \delta)^{2}}{9}$
• B. $\frac{(1+\cos \delta)^{2}}{4}$
• C. $\frac{(2+\cos \delta)^{2}}{9}$
• D. $\frac{(1+2 \sin \delta)^{2}}{9}$