2. :::::::: ENTITY CLASSES Select 710 significant business (entity) classes (also known as \"domain classes\") for a class model of Blackboard Learn, and explain your selections. \"Significant\" refers to the relative importance of the class in the internal software design. Describe their main responsibilities, attributes, and ftulctionalities. Describe two classes that you considered for this, rejected, and which are likely to appear in the final design. This question is not restricted to group discussion boards