Questions: Sarah is having a new sidewalk installed in front of her home. She negligently leaves the public sidewalk without a fence, sign, or other warning while under excavation. During the evening, Zach falls into the hole in the sidewalk. The darkness of night is: a. makes Zach contributorily negligent. b. an intervening cause of harm to Zach. c. a risk that Zach assumes. d. a superseding cause of harm to Zach.

The answer is b: an intervening cause of harm to Zach.

Explanation for each option:

a. Makes Zach contributorily negligent: This option would imply that Zach's own negligence contributed to his injury. However, simply walking on a public sidewalk at night does not typically constitute negligence on the part of a pedestrian, especially if there were no warnings or barriers indicating a hazard.

b. An intervening cause of harm to Zach: This option suggests that the darkness of night is a factor that contributed to the harm but does not absolve Sarah of her negligence. The darkness is a foreseeable condition that Sarah should have accounted for by providing warnings or barriers around the excavation site.

c. A risk that Zach assumes: This would imply that Zach voluntarily accepted the risk of walking on a sidewalk at night, knowing it was under construction. However, without any warnings or signs, it is unreasonable to expect Zach to assume such a risk.

d. A superseding cause of harm to Zach: A superseding cause would be an unforeseeable event that breaks the chain of causation, relieving Sarah of liability. The darkness of night is not an unforeseeable event; it is a normal condition that should have been anticipated by Sarah when leaving the sidewalk unprotected.

Therefore, the most appropriate answer is b, as the darkness is an intervening factor but does not relieve Sarah of her responsibility to ensure the safety of the sidewalk during construction.