The electronic configuration of $X$ and $Y$ are given below:
$X: 1s^2 2s^2 2p^6 3s^2 3p^3$
$Y: 1s^2 2s^2 2p^6 3s^2 3p^5$
Which of the following is the correct molecular formula and type of bond formed between $X$ and $Y$?

• A
  $X_3 Y$,ionic bond
• B
  $X_2 Y_3$,coordinate bond
• C
  $XY_3$,covalent bond
• D
  $X_2 Y$,covalent bond