The particles $\text{K}^+$ and Ar may be written as $^{39}_{19}\text{K}^+$ and $^{40}_{18}\text{Ar}$. Which of the following statements about these particles is correct?
- AAr has more neutrons than $\text{K}^+$.
- BK has more nucleons than Ar.
- C$\text{K}^+$ has 20 electrons.
- D$\text{K}^+$ has a greater mass than Ar.