If you have just walked into a dark movie theatre in the middle of the day, you may not be able to determine which seats are empty and which are full because it can take a long time for to occur.

...because it can take a long time for dark adaptation to occur.

Explanation:

Dark adaptation is the ability of the visual system to adjust to new levels of illumination, recovering sensitivity after exposure to light - such as when we go from the outdoors to the indoors. This process of adjustment includes the dilation of the pupil, as well as an increase in sensitivity of the retinal rods, even though the recovery is faster in the cones.

its d. you give me brainliest

well this isn't a question but if you are asking if it is true or false it is, true.