If the lines of regression coincide, then the value of the correlation coefficient is:
Explanation for the correct option:
If the two lines of regression coincide, then the value of their coefficient correlation will be or .
When the coefficient of correlation is perfectly negative or positive that means the two regression lines will be coinciding.
Amongst the given options, isn't available.
So, correlation coefficient is .
Hence, option (B) , is the correct answer.