Solve it correctly please. I ll rate with multiple votes. TYPED answer only. Show complete explanation.

The association between environmentally released mercury and autism rates in Texas was investigated using data from the Texas Education Department and the United States Environmental Protection Agency. There was a significant increase in autism rates with increases in environmentally released mercury. On an average, for each 1000 lb of environmentally released mercury, there was a 61% increase in the rate of autism.

The above is an example of which type of study design?

Cross-sectional study

Case-control study

Ecological/Correlational study

Cohort study