Question #N1308

The author's tone is best described as admiring, but the writer also acknowledges the potential downsides of the subject in the second sentence. The author emphasizes the significance of this by using a transition word. What word is used to make this shift in the author's tone?

What transition word does the author use to signal the shift in tone in the second sentence of this passage?
A. And
B. But
C. However
D. Therefore