Answer:
a. Hiring former employees from other companies and assessing their knowledge.
Explanation:
"Benchmarking" is a process conducted by a company when it wants to compare its performance with other competitors. In order to do this, the company needs to look into specific metrics and approaches in order to analyze their company's operation and how well it does compared to others.
Hiring former employees from other companies and assessing their knowledge is not a typical/common strategy in order to obtain benchmarking data. Not many companies would like to rehire and if they ever do, it will be hard to use the benchmarking data since the former employee's company might be totally different from yours. Remember that competitive benchmarking is only done when you want to compare with your competitors in the same field of business.
