The main objective of maximum constitutions is to determine and limit the authority of the government. It gives the formations for the functioning of the country such as tribunals and legislature and restricts the authority e.g. to jail without hearing for the government.
The main purpose of most constitutions out of these possibilities is D) to define and limit government power. It is usually not E) to give the government absolute power, but is a possibility. It is also not necessarily A) to define a moral code for the people to follow, and it also is not necessarily C) to prevent a strong central government because often constitutions create strong central governments.
The dust bowl was a sever drought caused by fluctuations in ocean temperatures. Other factors that contributed to the affect it had on the Midwest was the dry climate and their use of poor farming techniques.