The process by which a legislator votes in favor of the legislation of other lawmakers in order to gain support for her own legislation is known as logrolling.
I believe the answer is: C. unoccupied lands.
<span>The act was aimed to give the government more land for economic purposes (such as place for settlements or acquiring it resources).
This act lead to the mass migration of native Americans to western territories of the united states</span><span />
I think that the key point here is the "easily reproducible" - because all of them can be scientific questions (even a! it could tell us about about the human psyche!)
but d. is the best answer for a reproducible experiment. B could also make a good experiment, but it would be too expensive to be easily reproducible. C is calling for a more complex analysis that is too complex for an experiment. And a would require more questionnaires than experiments
