The correct answer is 4 - "All of the above".
Employers receive a lot of resumes. They need a way to filter out candidates who are not a good fit.
If your resume is generic, it won't capture the recruiter's attention. Human beings have a bias toward specificity. The more specific your resume is, the more likely you will get the interview.
Employers are using automated applicant tracking systems that discard resumes that don't include certain terms.
You might have a good resume, but if you don't include these terms and keywords, the software will discard your resume without being seen by anybody.
If an employer compares 2 resumes, and one is matched to the needs of the job and the other isn't, which one do you think he'll prefer?
As I said above, being specific is important. Generic resumes get discarded.
Other resume writing tips: