Which of the following will be coloured in aqueous solution?

A. Mn²⁺

B. Sc³⁺

C. Zn²⁺

D. Co²⁺

E. Fe³⁺

Choose the correct answer from the options given below:

A, D, E only

A. Mn²⁺: [Ar]3d⁵ 

B. Sc³⁺: [Ar]

No electrons in d-orbital.

C. Zn²⁺: [Ar]3d¹⁰

D. Co²⁺: [Ar]3d⁷

E. Fe³⁺: [Ar]3d⁵

A, D and E are coloured as they contain partially filled d-orbital and d-d transition can take place which is not the case with B and C.