Which of the following reactions is called roasting?

• A
  $ZnCO_{3(s)} \xrightarrow{\Delta} ZnO_{(s)} + CO_{2(g)}$
• B
  $2ZnS_{(s)} + 3O_{2(g)} \xrightarrow{\Delta} 2ZnO_{(s)} + 2SO_{2(g)}$
• C
  $ZnO_{(s)} + C_{(s)} \xrightarrow{\Delta} Zn_{(s)} + CO_{(g)}$
• D
  $Zn_{(s)} + H_2O_{(g)} \xrightarrow{\Delta} ZnO_{(s)} + H_{2(g)}$