Final answer:
Readers know the sailors in 'The Rime of the Ancient Mariner' considered the killing of the albatross wrong due to their changing reactions and the symbolic act of hanging the dead bird around the mariner's neck.
Step-by-step explanation:
In Samuel Taylor Coleridge's poem 'The Rime of the Ancient Mariner,' readers can infer that the sailors thought killing the albatross was wrong through their reactions to the act. After the mariner kills the bird, which was considered a good omen, the crew initially approves the act but, as misfortune ensues, they change their stance. This shift is evident when the sailors hang the dead albatross around the Ancient Mariner's neck as a sign of guilt and blame, symbolizing that they believed the act brought about their doom and was a moral transgression.