In which of the following ions, the colour is not due to d-d transition?

Which of the following complexes may be coloured due to d-d transition ?

Which of the following complexes may be coloured due to d-d transition ?

In which of the following transition metal ion complexes, the colour in not due to d-d transition?

If the colours of salts of transition elements are due to the presence of unpaired electrons in the transition metal ions, which of the following ions will be colourless in aqueous solution