Explanation:

- Formal Institutionalization: This concept involves structured and defined roles, rules, and procedures within an organization. Human Relations Theory critiques this by emphasizing that humans are not just parts of a machine. They have needs and emotions influencing their work.

- Human Motivation: This is a core focus of Human Relations Theory. It considers how employees' emotions, relationships, and needs affect their productivity and satisfaction.

- Informal Functioning: Recognizes that much organizational activity happens through informal social networks and personal relationships, aligning closely with the Human Relations Theory's emphasis on social factors.

- None of the above: This option implies that none of the listed concepts are rejected by Human Relations Theory.

The correct answer is formal institutionalization, as Human Relations Theory challenges rigid structures and emphasizes human elements.