Which of the following is a mandatory targeting field within audience setup in Campaign Manager?

Location is a mandatory targeting field because LinkedIn campaigns must deliver ads to users in a specific geographical area. This ensures relevance and compliance with regional advertising regulations. Without a specified location, the campaign would have no defined audience to target. Job Title, Company Size, and Audience Expansion are optional targeting fields that allow for more granular audience refinement but are not required for a campaign to be launched. You can run a campaign without specifying job titles or company sizes, and Audience Expansion is a feature to broaden reach, not a fundamental targeting requirement.