Is the bond formed between each pair of atoms pure covalent (a. k.a. nonpolar covalent), polar covalent, or ionic? (a) I and I (b) Cs and Br (c) P and O

Electronegativity
Which of the following sets of elements is in the correct order of increasing atomic radius (smallest one first, etc.)?
A) Ga, Ge, As
B) B, Al, Ga
C) I, Br, Cl D) As, S, P E) P, S, C