Outsourcing is well known as just an exercise which takes occurs when a company, therefore the answer is "Option b" that is "Outsourcing", and the further discussion can be defined as follows:
It gives another business a task to perform or to undertake for them rather than themselves.
It is an agreement between the two companies, usually for a specified period.
It is made to be better efficient and to minimize the costs.
In the large marketing company agreements for worker cheques with such a payroll service provider, they outsource people.