If each root of the equation (x² - 11x + 13 = 0) is diminished by 4, then the transformed equation is:
a) (x² - 3x - 11 = 0)
b) (x² - 7x + 1 = 0)
c) (x² - 15x + 45 = 0)
d) (x² + 5x - 3 = 0)