Among the following series of transition metal ions,the one where all metal ions have $3d^2$ electronic configuration is

• A
  $Ti^{4+}, V^{3+}, Cr^{2+}, Mn^{3+}$
• B
  $Ti^{2+}, V^{3+}, Cr^{4+}, Mn^{5+}$
• C
  $Ti^{3+}, V^{2+}, Cr^{3+}, Mn^{4+}$
• D
  $Ti^{+}, V^{4+}, Cr^{6+}, Mn^{7+}$