The answer to your question would be d.aquifer Hope this helps:)
Answer: Appalachian Mountains, Rocky Mountains, Great Lakes, Lake Superior, Missisippi River, Great Plains, Silicon Valley, Atlantic Ocean, Pacific Ocean, Mount McKinley.
Explanation: Sir I'm pretty sure you could've just looked these up, but those are all the Geographic features I can think of,
Because it is the difference of height and depth we should add
1684+216=1900
