What were the early issues and problems with the development of emergency management systems in the U$.$S$.?$

a$)$ Communication and efficiency problems existed across different federal agencies and departments.

b$)$ Frequent reorganization of office and authorities led to confusion and redundancy.

c$)$ Early civil defense directors came from the military and reflected that topdown culture, and in many cases only addressed emergency issues on a parttime basis.

d$)$ All of the above