The ratio of charge to mass, $r$, for a particle is defined by the equation below. $r = \frac{\text{charge on particle}}{\text{mass of particle}}$ The value of $r$ is found for an $\alpha$-particle, a $\beta^+$ particle and a proton $p$. Which list places the particles in order of increasing magnitude of $r$ from left to right?
- A$\alpha \rightarrow \beta^+ \rightarrow p$
- B$\alpha \rightarrow p \rightarrow \beta^+$
- C$p \rightarrow \alpha \rightarrow \beta^+$
- D$p \rightarrow \beta^+ \rightarrow \alpha$