Corelation between two dichotomous variables

I have a data from a research with responses (yes/no) about three questions (A,B,C) and I would to see if the variables are correlated.
First of all i compared the proportion of agreement(yes-yes, no-no) of them. The results was:
A-B= 78%
B-C is out of my objective.
So I run a Pearson Correlation test, and the results was:
A-B=0,17 (p-value = 0,03)
A-C=0,11 (p-value=0,15)

Which test should I do to verify the correlation between these variables? Chi-square test?