Answer:
The answer is - Epidemiological studies
Explanation:
The options are;
a. Clinical studies
b. Basic medical research studies
c. Market research studies
d. Epidemiological studies
The answer is D- Epidemiological studies.
Epidemiology deals with the study of diseases in human or animal population, how they occur, when the occur and where they occur. It helps determine the factors associated with diseases and what factors can help protect against these diseases. 
Epidemiological studies are used to estimate the frequency of a disease and find potential causes for the occurrence of the disease.
Therefore scientist carry out epidemiological studies through the use of interviews, surveys and measurements in order to study a large group of people.
 
        
             
        
        
        
Answer:
Grandmother hypothesis
Explanation:
The grandmother hypothesis is the result of a further developed mother hypothesis. The mother hypothesis suggests that the energy required to keep a woman fertile is better used in order to ensure that her offspring reproduce.
The grandmother hypothesis suggests that the grandmothers bolster the efforts of the mothers and make sure that their grandchildren's genetic interests are met. The grandmothers' can also increase the grandchild's social circle further increasing their chance to mate.
 
        
             
        
        
        
Sara is probably unpopular.
In general, people acted silly in front of their peers in order to gained attention from their social group.
Combined with the fact that Sara is insensitive to her friend's feeling, we could conclude that Sara is not received very well among her social groups despite her efforts to gained attention.
        
             
        
        
        
Hey there,
<span>Without </span>directions, and the ability to obey given instructions<span>, many unnecessary or unwarranted side effects may occur.
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Hope this helps :))
<em>~Top</em>