Which three members must have the private access modifier to ensure that this invariant is maintained?

Given: This class needs to protect an invariant on the sum field. Which three members must
have the private access modifier to ensure that this invariant is maintained?

A.
The setY ( ) method

B.
The x field

C.
The y field

D.
The sum field

E.
The ComputerSum ( ) constructor

F.
The setX ( ) method