The figure below is a forest plot taken from a meta-analysis of randomized clinical trials that evaluated the effect of peptides derived from food proteins on blood pressure. The figure below is displaying the relationship between the peptides and diastolic blood pressure. How many studies showed a positive association between food peptides and diastolic blood pressure. (In other words how many studies showed that food peptides increased blood pressure)?
a- None
b-Eleven
c-Three
d-Thirteen
