What is the primary goal of educational apprenticeships, as opposed to schooling

Had to look for the options and here is my answer.

The main goal of apprenticeships, as opposed to schooling is "to teach people specific trade skills." Why this is opposed to schooling because in school, we only learn the basics but general knowledge. Once apprenticeship is achieved, this is when they are able to improve a set of skills that is only applicable for that certain profession or job. 

A., d., and f i think