A zone stays the same length, I zone and h zone get shorter
D because no human has the ability to make their own food within themselves.
You should consider how much you will eat, what materials you will use during the trip, how many days you the trip would last, how to budget what you can ideally bring without being overloaded, and what emergency stuff you need to bring, just in case something gets out of hand.
I believe it is the frequency, because when a oscillation occurs that is the starting point to determine when another wave is to come.
