Answer:
2. If the transmission axes are crossed, it will be very dark when you look through the polaroid sheets
Step-by-step explanation:
Polaroids sheets produces linearly polarized light from an un polarized light. Now, when two polaroids are kept in such a way that their transmission axes are crossed ( that is 90° to each other). No light would pass to the other end, because their transmission orientation are different.
Thus, the correct answer to the question will be
2. If the transmission axes are crossed, it will be very dark when you look through the polaroid sheets
and rest all options are wrong because they all talk about some kind of brightness.