Your answer would be A, hope this helps : D
The answer would be a fragment because to be a sentence, groups of words need to have at least one independent clause.
Answer:
In line 28 we can see a shift in the speaker's focus to speculation about the limits that nature has.
Explanation:
In line 28, the speaker's approach changes and he begins to address nature in a more influential and profound way, showing the limits of it. This is to show that even something great like nature, has fineness, that is, it has limitations. This can be applied to the physical sense of nature, or even to the subjective and more conceptual sense of the effect of nature.
The answer is number 2. This is because when you skim text you just glance at it to figure out the topic.