Who has permission to delete files in this directory?

When a user runs s l the following output is displayed:
drwxrwxrwt 3 john1 users2 4096 Aug 06 13:42 research

Who has permission to delete files in this directory?

A.
Only root and file owner

B.
Only root, file owner, and group owner

C.
All users

D.
Only root and group owner