I will give the answers, not that anyone cares.

1. What is the largest  park in the National Park system?

Wrangell-St. Elias  2.2 million acres  Alaska

2. Which NP unit holds the largest Cave system in the World?

Mammoth Cave , Kentucky

3. What is the tallest monument  (man made structure) in the National Park system?

The Gateway Arch, St. Louis.   2d is the Washington Monument.  3d is Perry's Victory Monument

4. What park has the deepest lake in the USA?

Crater Lake

5. A. Which park hosts the tallest peak in  North America?

Denali  NP  (McKinley/Denali)

B. Which park hosts the tallest peak in the Continental US?

Sequoia NP  California  (Mt. Whitney)

6. What park hosts the lowest point in N. America?

Death Valley  NP   Cal.

7. What park hosts the hottest spot in the world?

Death Valley Cal.   (though I think I heard that the 134 deg. recorded in DV was surpassed by a 136 recorded somewhere in the Libyan desert)

8. A.Which park hosts the world's largest living tree...by volume?

Sequoia NP   Ca.   General Sherman tree

B. Which park hosts the world's tallest tree?

Redwoods NP  Cal.

9. Which park has the highest continuous paved road in the US?

Rocky Mountain NP,  Trail Ridge Rd.

10. Which NP is the busiest...i.e. has the most visitors?

Great Smokey Mountains NP

11. Which NP is the oldest...i.e. the first NP ever created?

Yellowstone NP

12. Which NP is the newest....i.e. most recently designated as a National Park (as opposed to some other NP unit designation)  Hint...as of February 2019.

Indiana Dunes NP

13. Which National Park  (designated as a National Park), is the least visited in the lower 48 states?   (so..not including Alaska/Hawaii...or US territories)

Isle Royale NP

14. What is the only National Park south of the Equator?

American Samoa NP

15. What is the snowiest National Park?

Mt. Rainier.       So...why is it not called Mt. Snowier rather than Mt. Rainier?   (Maybe it has the most rain as well?)