The total hardness in raw water is $500$ milligram per liter as $CaCO_{3}$. The total hardness of this raw water, expressed in milligram equivalent per liter, is
(Consider the atomic weights of $\text{Ca, C, and O}$ as $40$ $\text{g/mol}$, $12$ $\text{g/mol}$, and $16$ $\text{g/mol}$, respectively.)
- $10$
- $100$
- $1$
- $5$