This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
[{'content': 'Mosquitos decrease as height increases- \nSelect and explain. \nA. Positive correlation, B. Negative correlation, C. Bidirectional, D. Zero', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref:Parks 23rd edition pg 852 In order to find out whether there is significant association or not between the two variables , coefficient or Corelation is calculated . r lies between -1 and +1 r near -1 : indicates strong negative correlation . r = 0 : indicates no association r near +1: indicates strong positive correlation. Note: correlation does not necessarily prove causation .', 'role': 'assistant'}]