What are all the rational roots of the polynomial ( f(x) = 20x⁴ + x³ + 8x² + x - 12 )?
a. ( -4/5 ) and ( 3/4 - 4/5 )
b. ( 3/4 - 4/5 ) and ( -3/4 - 1 )
c. ( -1/5 ) and ( 3/4 - 4/5 )
d. ( -1 ), ( -4/5 ), ( -3/4 ), and ( 1 )