This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostats, Subject name: Social & Preventive Medicine
When correlation between two variables is very strong, the correlation coefficients will be:- 
Select and explain. 
A. >1, B. 1, C. 0.3, D. -1
B: 1
Answer: B: 1 
Explanation: CORRELATION: - Correlation is relationship between 2 quantitative or continuous variables. - Correlation is represented by: Scatter diagram/ Dot diagram. Correlation coefficient (r); Measures the degree or strength of relationship in a correlation Correlation coefficient (r) lies between : - 1 to + 1 (-1 < r < + 1) Positive correlation : 0 > r > +1 (+1 is perfectly positive/ strong correlation) Negative correlation: -1 < r < 0 (-1 is perfectly negative correlation) No correlation r = 0