Final answer:
The one adaptive coping mechanism Robert does not use to handle job stress is C) Substance abuse.
Step-by-step explanation:
Robert is in a highly stressful job and engages in various coping mechanisms to handle the stress. Among the listed coping strategies, the one he does not use, and which is not a healthy or adaptive method, is C) Substance abuse.
The other strategies listed, such as A) Seeking social support, B) Engaging in physical activity, and D) Time management, are all effective ways to cope with job stress and are commonly recommended in stress management programs.
Substance abuse, on the other hand, is a harmful strategy that can lead to addiction and exacerbate stress in the long run, rather than helping to manage it.
Robert does not use substance abuse as a constructive coping mechanism to deal with job stress.
Therefore the correct answer is C) Substance abuse.