Which of the Following Are Reasons Why the Chemical Properties

Multiple Choice

Which of the following are reasons why the chemical properties of phosphorus are quite different from those of nitrogen,even though they are located very closely on the periodic table?
I.the greater electronegativity of nitrogen
II.the larger size of the phosphorus atom
III.nitrogen's ability to form stronger pi bonds
IV.the empty valence d orbitals on phosphorus

A) I,II
B) I,II,IV
C) II only
D) III,IV
E) I,II,III,IV