The two blocks A and B of equal mass are initially in contact when released from rest of the inclined plane. The  Coefficients of friction between the inclined plane A and B are   and respecti•æw. 
(A) If ${\mu }_{1 }> {\mu }_2$  , the blocks will always remain in contact. 
(B) If ${\mu }_1 < {\mu }_2$   , the blocks will slide down with different accelerations (if blocks slide)
(C) If  ${\mu }_{1 }> {\mu }_2$ , the blocks will have a common acceleration 1/2 $({\mu }_1+{\mu }_2) g \sin \theta$

(D) If  ​${\mu }_1 < {\mu }_2$   , the blocks will have a common acceleration $\frac{{\mu }_1{\mu }_{2}g}{{\mu }_1+{\mu }_2}\sin \theta$