A3. Natural light I_(0) is incident on a system of crossed polaroids The intensity of light that has passed through the system __ 1.0 2. (I_(0))/(3) 3. I_(0) 4(I_(0))/(2)

The correct answer is 2. $\frac {I_{0}}{3}$.<br /><br />When natural light $I_{0}$ is incident on a system of crossed polaroids, the intensity of light that has passed through the system is reduced by a factor of 3. This is because each polaroid in the system reduces the intensity of the light by half. Since there are two polaroids in the system, the intensity is reduced by a factor of 3 in total.