According to Durkheim, the problems associated with dynamic density are resolved by ______. Select all, but only those that apply.

A) a shift from organic to mechanical to solidarity
B) differentiation, especially in the division of labor
C) increasing rigidity and intensity of the collective conscious
D) the emergence of new forms of social organization

Durkheim argued that the problems associated with dynamic density, or the increase in the number and closeness of interactions among people in a society, are resolved through differentiation, particularly in the division of labor (B), and the emergence of new forms of social organization (D). These processes help societies adapt by creating more specialized roles and institutions, thereby facilitating the transition from mechanical to organic solidarity, not the reverse as stated in option A. Option C, increasing rigidity and intensity of the collective conscious, is more characteristic of mechanical solidarity and does not resolve the issues of dynamic density according to Durkheim.