What do you want from Room when you create a DAO method and annotate it with @Update?

What do you want from Room when you create a DAO method and annotate it with @Update?

Example:

@Dao

interface MyDao {

@Update

fun updateUsers(vararg users: User)

}
A . Room generates an implementation that inserts all parameters into the database in a single transaction.
B . Room modifies a set of entities, given as parameters, in the database. It uses a query that matches against the primary key of each entity.
C . Room removes a set of entities, given as parameters, from the database. It uses the primary keys to find the entities to delete.