Paragraph: Metal nitrate (A) on heating decomposes, leaving a solid...

Paragraph:Metal nitrate $(A)$ on heating decomposes, leaving a solid residue $(B)$ which goes into solution with dilute HCl . The solution of (B) gives a white precipitate (C) with ammonium carbonate solution. The precipitate (C) is dissolved in dilute HCl and the solution is treated with potassium chromate to get yellow precipitate (D). The solution (B) with dilute $\mathrm{H}_2 \mathrm{SO}_4$ also gives a white precipitate $(\mathrm{E})$ insoluble in dilute HCl and nitric acid. The precipitate $(\mathrm{E})$ is a part of a white pigment lithopone.Question:The compound $(\mathrm{E})$ is :