I think its not important you just need to know how to use them in a sentence and kno what they mean there's no point in learning why there called verbs or proper nouns you just need to know "How do I use this noun in a sentence and sound correct?" that's what I think.
Answer:
It is a preposition because it cannot be either of the remaining three
A: Jupiter is the largest plant
its the answer because it’s true
I believe it would be B
Because they show topography the best
Hope this helps