Which one of the following complexes will most likely absorb visible light? (Atomic numbers: Sc=21, Ti=22, V=23, Zn=30)

a) [Sc(H₂O)₆]³⁺
b) [Ti(H₂O)₆]⁴⁺
c) [V(H₂O)₆]²⁺
d) [Zn(H₂O)₆]²⁺