I think that it is c just because it seems to fit the sentence
Answer:
For example, when A sees B drowning and fails to save him, A may be drinking, singing, whistling, or dancing while not saving B, but this is still classified as omission in the legal context (requiring a duty to act in order to convict) since these actions are not related to the result.
I believe that it means we never know our full potential, and that we never know how great we are till we are asked to show it.
Https://www.enotes.com/homework-help/what-bruno-gretel-see-outside-their-window-boynes-567137 this site has the answer.
