Robert M. La Follette Sr. is actually a former member of the U.S Senate. And according to him, the three groups of people that should help politicians draft laws would be retired politicians, labor leaders, and university professors. Why these three? Retired politicians already possessed the expertise in drafting laws after years of service. Labor leaders include those people who are exposed in the labor services and therefore, they know which one should be good and not and what other laws can be applied in the labor sector. Lastly, the university professors. These professors are already very knowledgeable in terms of laws and they understand the full context of the laws. Hope this answer helps.
The option that does not explain why a large part of the Great Plains became known as the "Dust Bowl" would be that "<span>The soil of the Great Plains was too rocky to support farming," since the soil was (usually) relatively fertile. </span>