Answer:
The type of sampling used in Jankowski's study of gangs is Option D. Stratified sampling. 
Explanation:
With stratified sampling, the researcher will partition the population into different groups, usually based on some characteristic that is common to that group. In this case, it was the different kinds of gang membership. Then, the researcher will take a sample of people within each specific group using another sampling method like simple random sampling for instance. The groups that are used in stratified sampling are called strata. Another example would be a national survey that is divided into strata of the different major ethnic groups that comprise the national population. 
 
        
             
        
        
        
Technology and Government Policy 
        
             
        
        
        
That statement is false
antidepressants work by reducing the reuptake of  neurotransmitters that exist in our brain. Antidepressant wont reduce the symptoms and behaviors, it only reduce the intensity of response that we usually have. Because of this, antidepressant usually could be resulted in loss of appetite and sexual drive.
 
        
                    
             
        
        
        
Answer:
The on-line research strategies that raises the most concerns regarding ethical principle of respecting the autonomy of research subjects and the corresponding federal regulations requiring informed consent are: C) and D).
Explanation:
C) A researcher observing an open support group whithout announcing her presence is an alteration of both respecting the autonomy of the research subjets and also doesn´t consider the regulations requiring informed consent.
The subjects should know they are being subjtect of a research, to see if they agree or not. The researcher by not annouincing her is not respecting their autonomy to decide.
D) If a researcher poses to be a survivor from cancer when not, to be able to get closer to people that are; she is violating both the respecto for autonomy on the research subjects and also she is braking the informed consent.