Find any points of discontinuity for the rational function. What are the points of discontinuity? Are they all removable?
y = (x-7)(x-3) / x^2-10x+21

A. x = 1, x = –8, x = –2; yes
B. x = 7, x = 3; yes
C. x = –7, x = –3; no
D. x = –1, x = 8, x = 2; no