Answer: Standard edition
Step-by-step explanation:
Based on the information given in the question, the edition of Windows Server 2016 that is most appropriate for this situation will be the standard edition.
Since it's going to be fora small server to provide basic file services to faculty, staff, and students in that department, which currently has 122 users, the standard edition is appropriate.
Standard edition is ideal in a scenario whereby there's a non-virtualized environments or low density with regards to the population.