Which of the Following Defines Job Posting

Which of the following defines job posting? 

A)  ​It is a planned sequence of jobs through which employees may advance within an organization. 
B)  ​It is a procedure for advertising job openings within a company to existing employees. 
C)  ​It is a written description of the basic tasks, duties, and responsibilities required of an employee holding a particular jo B. 
D)  ​It is a purposeful, systematic process for collecting information on the important work-related aspects of a jo B.