This one is a simple sentence.
"Cache" - a collection of items of the same type stored in a hidden or inaccessible place.
Ex; In preparation of the drought, the farmer has stored a sizeable cache of water tanks.
The troops are looking for the former dictator’s cache of gold bars.
When digging in the backyard, I discovered a cache of antique coins.
Did the troops ever find the cache of nuclear weapons?
The archaeologist hopes to find a cache of artifacts on his next dig.
Characterization is when the author introduces his character(s). So I guess when you’re asked that question it means you have to find the character’s behavior, personality, appearance, thought process... etc