12. The potential energy U between two molecules as a function of the distance X between them has been shown in the figure. The two molecules are
(a) Attracted when x lies between A and B and are repelled when X lies between B and C
(b) Attracted when x lies between B and C and are repelled when X lies between A and B
(c) Attracted when they reach B
(d) Repelled when they reach B
Answer-b
(10)