B please let me know if I’m wrong :)
[ (a.) What in me is dark
Illumine, what is low raise and support; ]
That to the highth of this great Argument
[ (b.) I may assert th' Eternal Providence, ]
For the main reason that "it promoted sacrifice for the common good." the speech was commonly read during the Cultural Revolution. This speech was the primary political propaganda of Mao Zedong as a slogan during the dark times of the Chinese cultural history.