In hires which require recruiting resources and skills which the company does not possess or specializes in, which of the following would the company have the greatest benefit? To clarify greatest benefit I am referring to long term ROI (least cost to the highest efficiency and retention). It might surprise you how many options are available. Each comes with its own risks and rewards. Don't let it bother you if you are unfamiliar with some of these. The majority of HR officers would score low in this area. Educating yourself can make the difference in creating a lower cost highly efficient recruiting solution vs a higher cost sluggish fix with little control and increased liability. 

Educating yourself on the differences, similarities and your company's assumed liabilities can also prevent future legal threats to your organization. 

Below I have listed most if not all the possible choices:

(a) Third-party recruiting agency (managed)

(b) Remote independent recruiter (non-managed)

(c) Staffing agency (managed)

(d) Having a staffing agency provide a recruiter on contract (co-managed)

(e) Hiring the recruiter as a direct hire temporary  employee

(f) near shoring agency / RPO

(g) off shoring agency / RPO

(h) in sourcing / RPO

(i) Third-party RPO (using US recruiting labor pool)

(j) Direct hire temporary recruiter under under PEO agreement

(k) Staffing agency or recruiting agency or RPO which uses a PEO agreement or back office vendor  who becomes the employer of record for a recruiter who is assigned to the client company