Q$1.$ A hammer tool can only be used by one technician at a time to perform hitting. Accordingly, you have developed a Hammer class with a hit method. Objects of class Hammer are used to simulate different hammers, while threads are created to simulate users. Which situation needs to add the synchronized keyword to the hit method?

A$.$ Two users use one hammer.

B$.$ Two users use two hammers with one for each.

C$.$ One user uses one hammer.

D$.$ One user uses two hammers.

E$.$ All of the listed answers