40. A box slides to the right across a horizontal floor. A person called Ted exerts a force T to the right on the box. A person called Mario exerts a force M to the left, which is half as large as the force T. Given that there is friction f and the box accelerates to the right, rank the sizes of these three forces exerted on the box.
(A) f<M<T
(B) M<f<T
(C) M<T<f
(D) f=M<T
(A) f<M<T
(B) M<f<T
(C) M<T<f
(D) f=M<T