Answer:D - the employee's coworkers
Explanation: Insofar as appreciation is concerned the most influential on perceptions of appreciation for an employee are the employee's co workers.
Who are co workers? They are the people a person interacts with, work with and spend the day with in an office environment.
They are the most influential on perceptions of appreciation for an employee.
This is so because they they know each other well and can talk to a large extent about a co worker.