Let S be the set of all non-zero real numbers α such that the quadratic equation αx2−x+α=0 has two distinct real roots x1 and x2 satisfying the inequality ∣x1−x2∣<1.
Which of the following intervals is (are) a subset(s) of S ?
a. (−21,−51)
b. (−51,0)
c. (0,51)
d. (51,21)