A photodetector measures the intensity of light from two different sources, $S_1$ and $S_2$.

A polarising filter is placed between source $S_1$ and the detector. When the filter is rotated through a small angle, the detected intensity of light from $S_1$ decreases.

When the same filter is placed between source $S_2$ and the detector and rotated through any angle, the detected intensity remains constant.

Which row in the table correctly identifies the polarization state of the light waves from $S_1$ and $S_2$?