Light with intensity $I_0$ that is vertically polarised is incident normally on a polarising filter. The filter’s transmission axis makes an angle $\theta$ with the plane of polarisation of the light. After the light passes through the filter, its intensity becomes $\dfrac{I_0}{3}$. What is $\theta$?
- A$8.4^\circ$
- B$55^\circ$
- C$71^\circ$
- D$84^\circ$