For important management positions companies often use

The correct answer would be Specialized Executive Search Firms.

Explanation:

When companies hire employees, they usually use the conventional methods of recruitment, like giving ads in newspapers or pasting ad on a social job site, etc. But when employees for the important management positions are required to hire, companies often use Specialized Executive Search Firms. These are the recruitment firms which takes the demands of the employer and search for the best of the best candidates to be interviewed by the employers. Such firms have fine data about the best candidates in their databases which updates regularly. Also, after selecting the candidates, they first take initial interviews of the potential employees themselves and then route them to the employer.