Complete the Following Chart, in Order from Left to Right

Multiple Choice

Complete the following chart, in order from left to right $\begin{array}{|c|c|c|c|c|}\hline \text { Isotope } & \text { Mass Number } & \text { Protons } & \text { Neutrons } & \text { Electrons } \\\hline & 40 & 19 & & 19 \\\hline\end{array}$

A) (⁴⁰Zr) , 21
B) (¹⁹K) , 40
C) (²¹K) , 19
D) (⁴⁰K) , 21
E) (³⁸Sr) , 19