How did legalism help Shi Huangdi centralize Han power? Select all that apply

How did legalism help Shi Huangdi centralize Han power? Select all that apply. (2 points)

A. It declared that man’s nature is good and is best governed by a virtuous and fair ruler.
B. It emphasized that the strength of a ruler rather than his goodness was most important.
C. It maintained that only a greedy ruler could set a strong and convincing example for people.
D. It asserted that people are greedy, and only tough laws and punishments can maintain order.