Answer:
Option C - feed-forward activation.
Step-by-step explanation:
Feed forward, or feedforward, is a term describing an element or pathway within a control system that passes a controlling signal from a source in its external environment to a load elsewhere in its external environment.
A goes to B which goes to C....
In this case, there were those 10 people sitting in a row. The signal was meant from this enviroment only. The second person wakes up the ninth to save the system (the chain of the signal) from failling and not reaching the end.