Question

A human resource manager is writing an employee handbook and wants to use a formal tone. Which sentence states a rule in the most formal manner?

a. You shouldn’t ever forget to wear your ID card at work.
b. Security won’t let you in if you don’t wear your identity card at work.
c. One must wear one’s identity card at all times when at work.
d. Wear your ID card at work if you don’t want to get into trouble.

Answer 1

c. One must wear one's identity card at all times when at work

Using the pronoun "you" makes it less formal. Since c doesn't use "you" it's the most formal.