$3 d ^{0} \quad 3 d ^{10}$

(B) $Ti ^{4+}, Cu ^{2+}$

    $3 d ^{0} \quad 3 d ^{9}$

(C) $V ^{2+}, Ti ^{3+}$

      $3 d^{3} \quad 3 d^{1}$

(D) $Zn ^{2+}, Mn ^{2+}$

      $3 d^{10} 3 d^{5}$

No $d-d$ transitions in ions with $d^{0}$ and $d^{10}$ configuration. Therefore they are colourless.