Final answer:
All of the listed skill sets - functional, work content, and adaptive or self-management skills - are considered transferable, valuable to employers for their adaptability across different roles.
Step-by-step explanation:
The type of skill considered transferable is d) All of the above. This encompasses functional skills such as time management, work content skills like specific knowledge or abilities pertinent to a job, and adaptive or self-management skills which include the capacity to adapt to changes and manage oneself in various circumstances. Employers value transferable skills due to their versatility and the broad contribution they can make to various tasks across different job roles and industries.