Answer:
c Accidentally
Explanation:
According to the sentence given, Christopher Columbus had limited knowledge of world geography and inaccurate navigational devices; and as a result of this, he was able to accidentally discover North America and all the available riches there.
The word "inadvertently" as used in the sentence means accidentally.
The government holds us to our own. We have no say, it's the government's buildings that hold the sky.
It is a noun because that is the main thing in you story/sentence