Answer:
2. an official statement that an individual is qualified to do a particular job and has specific knowledge and expertise
Explanation:
I'm not sure if this question relates to a specific text or an article, but in common use, this word denotes a process of attaining a certificate, which is a formal document that claims a certain object, person, company etc. meets all the criteria necessary.
Obviously, here, it refers to cerification of medical workers which means, in the given context, that it represents a statement which officially confirms an individual's qualifications for a job.
