The graph in the passage shows the solubilities of some compounds (salts). ... ...

The graph in the passage shows the solubilities of some compounds (salts). Which of the following is most likely true regarding the Compounds A, B, C and D?  
(A) The solubility process of Compound B is exothermic, and those of Compounds A, C and D are endothermic.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in 08. Chemistry of Solutions