The answer to this question is subliminally
In psychology, subliminal refers to an occurrence when the stimuli that we receive is not intense enough to attract our conscious attention.
For example, our heart beats every time but we rarely realize it happened because the stimuli is not strong enough
The code Nior was also known as the slave code so your answer would be D the slave population.
D. Regular river flooding
Your choice. I pick Mid-Atlantic, but I don't know why.