Adrian is a researcher who works in a lab. He decides to perform an experiment to understand the side effects and benefits of drinking tea. He puts forth some questions about the experiment. They include, Do people who drink tea have a higher risk of brain illnesses than non-tea drinkers? and Do people who drink tea stay more alert than non-tea drinkers? He also proposes a question, Are people who drink tea happier than people who don’t drink tea?

Adrian is performing a research based on co-relational research design which allows him to use various variables and compare the relationships and patterns existing between them.

Explanation:

Co-relational studies include case-control studies and observational studies.

Adrian is researching about the benefits and side effects of drinking tea. To support his theory, he collects evidence based on questionnaires provided to people. He questions about the alertness and happiness level after drinking tea and about risks of getting brain illness with drinking tea. He will co-relate all the results obtained and will conclude his research about the benefits and side effects of drinking tea.  

d i think its   answer d

i'm guessing this is from edg enuity so the answers would be, from top to bottom,

theodor schwann

matthias schleiden

robert hooke

rudolph virchow

anton van leeuwenhoek