The photon energy released from the transition from n=3 to n= 1 is equal to the sum of the photon energy released from the transition from n=3 to n=2 and from n=2 to n= 1.

That is: hv 1=hv2+hv3, so V 1 = V2+V3.

Because the photon energy released from the transition from n=3 to n= 1 level is greater than that from n=2 to n= 1 level, V 1 > V2.

The energy released from the transition from n=2 to n= 1 is greater than that from n=3 to n=2, so V2 > V3.

According to λ=cv: λ 1 < λ 2, λ 1 < λ 3, so C is correct, and A, B and D are wrong.

So choose: C.