Answer:
A. intern
Step-by-step explanation:
An Intern is an individual or a student or trainee who works, often with very little or no pay, for the purpose of gaining work experience or meet requirements for a qualification most specifically, a university credit, often referred to as industrial attachment.
Hence, one way to explore a career opportunity is to work as a trainee in your field of interest to gain practical experience. In this experience you would be known as an INTERN.