A sample of magnesium contains only the isotopes $^{24}\text{Mg}$, $^{25}\text{Mg}$ and $^{26}\text{Mg}$. The percentage abundance of $^{25}\text{Mg}$ and $^{26}\text{Mg}$ is equal. The relative atomic mass of magnesium in the sample is $24.3$. Calculate the percentage abundance of $^{24}\text{Mg}$.
- A10%
- B20%
- C60%
- D80%