If $c<a<b<d$, then roots of the equation $b x^{2}+(1-b$ $(c+d)) x+b c d-a=0$
(A) are real and one lies between $c$ and $a$
(B) real and distinct in which one lies between $a$ and $b$
(C) real and distinct in which one lies between $c$ and $d$
(D) roots are not real