solved I’m working on a health & medical project and need

I’m working on a health & medical project and need an explanation to help me understand better.

Based on the topic you chose in Unit I ( Obesity in America) you will describe the research design and methodology you plan to use to complete your research (remember this is a hypothetical research study that you will not conduct). You will include and discuss the type of data you will collect and consider the following questions:

Describe the three types of research designs, and explain what method you will use to collect data (qualitative, quantitative, mixed methods).
Why did you choose this approach?
What type of tool (i.e., survey, interview, observation) will you use to collect data?
Explain why you will use that type of data collection tool.
Explain how you will ensure internal and external validity in your research project.