Can you help me I stressing out like every time I send it a link pops up like I want he answer

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

Plz ! ive been stuck on this forever

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation