The correct statement about d-block elements is
they are metals
they show variable valency
they form coloured ions and complex salts
all the above statements are correct
d-block elements -
1) They are metals
2) They show variable valency
3) They form coloured ions and complex salts
They form coloured compounds and coloured complexes. They have vacant orbitals electron takes up energy and move to higher energy levels and thus appeared coloured.
All these properties are exhibit by transition elements.