Which of the following represents the electronic configuration of an element with atomic number $17$?

• A
  $1s^2, 2s^2 2p^6, 3s^1 3p^6$
• B
  $1s^2, 2s^2 2p^6, 3s^2 3p^4, 4s^1$
• C
  $1s^2, 2s^2 2p^6, 3s^2 3p^5$
• D
  $1s^2, 2s^2 2p^6, 3s^1 3p^4, 4s^2$