A 2017 article from the American Journal of Public Health 1 reports the results from a randomized study designed to evaluate the efficacy of an intervention targeted to Hispanic/Latino men who identify as gay, bi-sexual or other men who have sex with men (MSM). A representative sample of 254 such men was randomized to be in either the intervention group (n=152) or the control group (n=152). The primary outcome under study was getting tested for HIV within the six-months following group assignment (randomization) among those who had been sexually active in this same six-month follow-up period. At six months of follow-up 141 subjects in the intervention group reported having had sex (with men and/or women) since randomization. Of these 141 men, 114 , i.e. 81%, were tested for HIV after being randomized to the intervention group. At six months of follow-up 147 subjects in the control group reported having had sex (with men and/or women) since randomization. Of these 147 men, 40 , i.e. 27% , were tested for HIV since being randomized to the control group. 4. What is the (approximate) estimated risk difference of getting tested for HIV for subjects in the Intervention group compared to subjects in the Control group?

a. 3.0

b. 0.54

c. 0.33

d. -0.54