Read the following paragraph: (1) Research shows that reading as a teen leads to success: when we teens read more than just our classroom assignments, we generally do well in school. (2) Why? (3) Pleasure-reading expands our vocabulary, shows us how different writers put down their thoughts—which leads to better writing skills and helps us develop our ability to understand and interpret complex ideas. (4) Also, the more we read, the more information we pick up, which leads to knowledge that is useful in our classes

Katherine would like to add the following detail to the paragraph above:

Teachers do not have nearly enough time to teach students all the amazing things there are to know.

Where should this sentence be inserted?
A. After sentence 1
B. After sentence 2
C. After sentence 3
D. After sentence 4

(It's either C or D but I'm not sure)