Dose response relationship is a measure of

Ans. is 'b' i.e., Strength of association* Likehood of a causal relationship is increased by the presence of the following criteria :1. Temporal association# It implies that suspected cause preceds the observed effect. It is the most important criteria.2. Strength of association# It implies how strongly exposure is associated with disease. It can be determined by relative risk (in cohort study), odds ratio (in case-control study), dose response relationship. and cessation of exposure (reversibility).3. Consistency of association# The association is consistent if the results are replicated when studies in different settings and by different methods.4. Coherence of association# The causal association must be coherent (supported by) with relevant facts.5. Specificity of association# It is implies a 'one to one relationship'. It is the weakest and the most difficult criteria to establish.6. Biological plausibility# It implies biological credibility to the association, that is the association agrees with current understanding of the response of cells, tissues organs and system to stimuli.# For example, positive association of food intake with GI cancer is biological plausable (food enters GIT and causes cellular response), while positive association of food intake and skin cancer is not biological plausible.