Providing a client with reading material on racism in the workplace may be most appropriate and helpful for a client identified as the type of the key model.

empirical

Explanation:

This would be the most helpful to a client identified as the empirical type of the key model. By providing this reading material you are providing the individual with an example on what is and isn't appropriate regarding this topic. The individual can observe the examples given and learn from them in order to apply them to his/her life and modify their behavior. Which learning from example and observation is what an empirical type individual tends to do.