Answer:
A
Explanation:
It's not a complete sentence. It leaves you hanging. It's only a <em>fragment</em> of the sentence. We don't know what Marshall did when he realized that Barney lied to him about the stain on the carpet.
It looks good.
You did a nice job being descriptive and your grammar looks fine.
Faustus first began to believe that human salvation was impossible because he read the scripture and saw that all human beings sin and are D word.
In addition, he had been misled by Mephastophills, who caused him to misread the scriptures.
I believe that it is D. Speculative