The decision about which level of check is appropriate depends on the level of check required by the requesting Agency.  Ultimately it is the Agency not the Police who would determine the most appropriate type of check.  If you're uncertain which level of check is required, you should consult with the requesting Agency.  They are in the best position to determine the level of check required. 

It is important to note that a Police Vulnerable Sector Check can only be be conducted where an applicant requires a Police Check for the purpose of being in a position of trust or authority with respect to a vulnerable person. Vulnerable persons include children, elderly persons as well other persons with cognitive, physical or emotional difficulties and puts them at risk of being exploited.