As Ethylenediamine Is Added to a Solution of [Ni(H₂O)₆]²⁺, the Water

As ethylenediamine is added to a solution of [Ni(H₂O) ₆]²⁺, the water molecules are replaced two at a time by ethylenediamine to produce the sequence of ions: [Ni(H₂O) ₆]²⁺, [Ni(en) (H₂O) ₄]²⁺, [Ni(en) ₂(H₂O) ₂]²⁺, and [Ni(en) ₃]²⁺. How does the color change through the sequence?

A) The color changes toward red with the addition of ethylenediamine.
B) The color changes toward purple with the addition of ethylenediamine.
C) Red, yellow, purple, blue with the addition of ethylenediamine.
D) There is no color change with the addition of ethylenediamine.
E) The color change cannot be predicted with the addition of ethylenediamine.