Researchers at an epidemiology clinic are interested in the difference in the incidence proportion of a number of severe nausea that occur during a clinical trial between the treatment and placebo groups. The following table describes the number of cases of severe nausea, reported over the course of the 10 year intervention.

	Nausea	No Nausea	Total
Treatment	267	1522	1789
Placebo	485	539	1024
Total			3080

How would you set up a null hypothesis to examine the relationship between the treatment and nausea? Let p1 = the incidence proportion of nausea in the treatment group, and p2 = the incidence proportion of nausea in the placebo group.

Group of answer choices

a. p1 = p2

b. p1 < p2

c. p1 > p2

d. p1 is not equal to p2