Successive ionization energies for an element, Z, are shown in the table below.

What is the most likely formula for the ion of Z?

A.     ${{\text{Z}}^ + }$

B.     ${{\text{Z}}^{2 + }}$

C.     ${{\text{Z}}^{3 + }}$

D.     ${{\text{Z}}^{4 + }}$

B