The existence of biases in the economic evaluations of the pharmacological treatments of attention deficit disease and hyperactivity resulting from the publication of research work can be caused by:

Select one:

a.The study has no sponsors and therefore it has not been published.

b.A research project with statistically significant results is less likely to be published than one with non-significant results.

c.All other statements are correct.

d.A research project with statistically significant results is more likely to be published than one with non-significant results.