The given passage talks about the history of Automated Tracking System. The passage talks about when this software was developed and for what purpose.
The passage follows a timeline that takes the readers step by step to the history of Automated Tracking System and its expansion, and how it begun to be used massively by the companies to hire an employee or to track resumes that matches the required skills by the company.
The passage also describes about the counter-industry that sprung up in response of ATS to protect and guard the resumes of employees from automated eyes.
So, the intended audience of the given passage is the people who are interested in the history of ATS. The passage follows the timeline. Thus the correct answer is option B.
Past tense is a grammatical tense used to describe an action or event that is done in the past. "Mixed" has a regular form "mix" and by adding "-ed" to it, it becomes a past tense.
