Final answer:
An instance of a work challenge stressor is a bank teller unexpectedly taking on management duties, which can lead to chronic occupational stress due to the increased workload and responsibility.
Step-by-step explanation:
An example of a work challenge stressor would be option e, where a bank teller is doing his regular job and also taking on some management duties because his boss quit unexpectedly. This scenario aligns with occupations that involve heavy workloads and little job control, which are factors contributing to chronic occupational stress. The bank teller faces both increased job demands and an expanded range of responsibilities with little preparation, leading to job strain.