Which statement is most accurate regarding inclusion and exclusion criteria?

The most accurate statement is Inclusion and exclusion criteria are always needed in some form. 

Inclusion criteria are the prospective subjects characteristics that should be taken into consideration in the study.
Exclusion criteria are set of predefined definitions commonly used to identify subjects who will not be included or those characteristics that disqualify prospective subjects for the study to be included

Which of these is a benefit of health care access that lowers the risk of chronic disease like skin cancer? a. higher incomeb. better doctorsc. early detectiond. safer environmentif this is your question it is c

Yes, this is very true. specifically causing damage in the  dentrite.