Question

what factor determines whether a college degree is necessary for a job?
the jobs location
the amount of people applying for the job
the technology requirements of the job

Explanation:

A job's technology requirements (e.g., specialized skills, knowledge from college - level education) determine if a college degree is needed. Job location and number of applicants don't relate to the need for a degree; they are about where the job is and competition, not skill/knowledge needs.

Answer:

the technology requirements of the job