Consider the following equation: Ag⁺ _(aq) + CI-_(aq) → Ag⁺CI- _(s) ; ∆H = _65.7 kJmol^-1. From the equation, it can be deduced that

• A direct combination is involved and the reaction is endothermic
• B a solid is formed and heat is evolved
• C activation energy is high and a catalyst is required
• D the reaction is endothermic and occurs at high temperature