Matilda sits on her back porch for one hour every morning for a week and record the types and numbers of birds that viste her bird feeder what kind of study is this ?

Step-by-step explanation:

The choices for this question are

a. Double-blind study

b. Experiment

c. Sample survey

d. Observational study

The right answer would be d. Observational study, because this type of study is defined as an empirical and non-experimental research where all information is obtained by observation. When we apply this study, we try to find a cause-effect relation by observing the phenomenon as it naturally happens, that is, without interfering with the course of events like experimental investigations do.

So, in this case, Matilda is just observing, without altering anything that could influence the birds. She just sits observe and recover information, that's an observational study.

Therefore, the right answer is d.