The figure below shows the per capita milk consumption and the age adjusted prostate cancer incidence in different countries.
120
United States
100
Australia
80
Brazil
Age-adjusted prostate cancer incidence
per 100,000 men
60
.
Sweden
40
Ireland
China
Thailand
Philippines
Korea
.
Spain
20
Poland
0
0
0
100
200
800
900
1000
300 400 500 600 700
Per capita milk consumption (g/d)
What is the study design?
A. Randomized controlled trial
B.Ecological Study
C.Case-control study
°D. Cohort Study