A new team of epidemiologists was tasked with examining the association between measles vaccination (exposure) and developing measles (outcome) in a retrospective cohort study of school children in Washington, D. C. during 2008. In 2008, 21 school children were diagnosed with measles while 138 children never acquired measles. Health records from 2004 showed that 18 of the 21 measles cases were vaccinated, while 134 of 138 non-cases were vaccinated. What following interpretation should the team of epidemiologists make regarding the calculated relative risk obtained in question number 28?

a. The relative risk is less than 1.0, indicating a decreased risk "for the exposed (vaccinated) children.
b. The relative risk is greater than 1.0, indicating an increased risk for the exposed (vaccinated) children.
c. The relative risk is equal to 1.0, indicating the risk for the exposed (vaccinated) children is equal to the risk in the non- exposed children.
d. Not sufficient evidence to generate an interpretation of relative risk.