Elements, compounds and mixtures — practice question

The production of sulfuric acid using the Contact process requires three different raw materials. Of these raw materials, how many are elements, how many are compounds and how many are mixtures?

• Aelements $0$, compounds $3$, mixtures $0$
• Belements $1$, compounds $2$, mixtures $0$
• Celements $1$, compounds $1$, mixtures $1$
• Delements $2$, compounds $0$, mixtures $1$