Answer:
The correct answer, indeed, for the question: How did Einstein´s Theory of Relativity change the way people thought about the Universe, would be: A: It made people think they lived in a universe that might not be fully understood.
Explanation:
From the very beginning of his work with the theories about the universe, light, matter, space and time, and how they work, as well as the theories of gravity, Einstein himself showed the world that nothing was absolute when it came to comprehending the universe and how the different factors work. During his lifetime he himself had to revise his own theories, especially that of relativity, several times, and consider that what the general population thought, also applied to him: the universe, how it came to be, and how it worked, was as much of a mystery yet, as the origins of life itself.