A solid sodium halide, NaX, is treated with concentrated sulfuric acid. In the products formed, the smallest oxidation state shown by sulfur is $+4$. Halogen $Y_2$ is less volatile than halogen $X_2$. Which sodium halide is NaX, and which halogen is $Y_2$?
- Asodium bromide; chlorine
- Bsodium bromide; iodine
- Csodium iodide; bromine
- Dsodium iodide; astatine