Elements up to atomic number $103$ have been synthesized and studied. If a newly discovered element is found to have an atomic number $106,$ its electronic configuration will be

• A
  $[Rn] 5f^{14} 6d^4 7s^2$
• B
  $[Rn] 5f^{14} 6d^1 7s^2 7p^3$
• C
  $[Rn] 5f^{14} 6d^6 7s^0$
• D
  $[Rn] 5f^{14} 6d^4 7s^2$