5. Which factor most contributed to violence that newspapers referred to as "Bleeding Kansas"? O A. abolitionists' attacks on the owners and overseers of new slave plantations in Kansas
O B. slave uprisings in Kansas that were fueled by arms shipments from radical abolitionists
OC. conflict between abolitionists and pro-slavery groups to win the slavery vote in Kansas
OD. the use of federal troops to break up protests by both abolitionists and pro-slavery groups

According to the federal regulations, which of the following studies meets the definition of research with human subjects? a study of twenty 4th grade classrooms in which researchers ask the schools to systematically vary the time of day reading is taught, and collect weekly assessments of reading comprehension for each child over a three-month period.the collection of data, by a playground designer hired by the superintendent of schools, about the physical dimensions of school playgrounds, presence of fencing, and the kinds of equipment currently provided.a feasibility study for implementing a year-round school program, focusing on economic issues such a facilities utilization and transportation costs.an analysis of aggregate data comparing statewide high school graduation rates provided by the state department of public instruction, using county tax information.