The "social person" hypothesis is a management-related humanity hypothesis put forward by organizational behaviorists. The "social person" hypothesis believes that the material benefits people get in the work are secondary to mobilizing their enthusiasm for production, and people attach the greatest importance to work. China is friendly with the people around it, and good interpersonal relationships play a decisive role in motivating people to work. According to the above definition, which of the following is a management method based on the "social person" assumption? ['Employee bonuses are linked to performance and a secret pay system is implemented.', 'Encourage and support employees to participate in vocational training in their spare time.', 'Implement different management measures for employees of different ages.', 'Upper and lower levels participate in research and discussion of corporate decisions to varying degrees.']