HELP PLEASE, I GIVE 50 POINTS!!!!!!

How is the electronegativity difference used in determining the type of bond that occurs between two atoms? (SELECT ALL THAT APPLY)

a) If the difference is between 0.4 and 1.7, it is polar covalent.
b) If the difference is greater than 1.7, it is mostly ionic.
c) If the difference is zero, the bond is considered nonpolar covalent.
d) If the difference is less than 0.4, it is mostly covalent.
e) If the difference is zero, the bond is considered mostly polar.
f) If the difference is greater than 1.7, it is polar covalent.
g) If the difference is between 0.4 and 1.7, it is nonpolar covalent.
h) If the difference is less than 0.4, it is mostly ionic.