$3)$ Take the same example from question $-$ the smoke plume containing chemical X$.$ Imagine you are now in charge of recruiting, analyzing, and assessing the public health implications of this event.

a$.$ What method do you use to find potential participants? $(2-3$ sentences$)$

b$.$ A colleague recommends recruiting people from the churches in the community. Are there any potential issues of bias that could occur with this? If so$,$ which bias and why is that a problem? $(2-3$ sentences$)$

c$.$ What variables would you collect from participants? Describe what your explanatory and response variables would be$.$