Sixty years ago, a high school diploma was the minimum requirement for entry into the paid labor force of the united states. today, a college diploma is virtually the bare minimum.
this change reflects the process of:

a. tracking.
b. credentialism.
c. the hidden curriculum.
d. the correspondence principle.

b. credentialism

Explanation:

Credentialism refers to what is required as proof or documents which shows that someone has a particular formal education qualifications. These credentials are crucial because they determine one's owns ability to perform a job or to establish if they have what it take to qualify for that job.

Some jobs or most jobs especially in the western part of the world requires that someone possesses certain credentials in order to be considered for a particular post or position.