The improvements in steel meant cities could finally grow up with the addition of
a. bridges
b. city parks
c. skyscrapers
d. sewer systems

I think it might be sky scrapers or bridges

The improvements in steel meant cities could finally grow up with the addition of skyscrapers.

Your correct answer is: C. Skyscrapers

Good luck with your studies, I hope this helps~!

That's true, it's a belief in one god

It is c because it shows how the author is stating their own oppinion about the protagonist