Prevalence Reports About Speech Sound Disorders Vary Because of Differences

Prevalence reports about speech sound disorders vary because of differences in the:

A) age range of the children studied, definitions of speech sound disorders, data collection methods, procedures for sampling children, and cut-points used on a standardized test.
B) statistical procedures for calculating prevalence.
C) the qualifications of the researchers determining prevalence.
D) inclusion or exclusion of incidence data.