Diet — practice question

The table gives the percentages of students from two schools who have one or more decayed teeth. What could account for these findings?

• AThere is less calcium in the students’ diet at school X than at school Y.
• BThere is less sugar in the students’ diet at school X than at school Y.
• CThere is less vitamin C in the students’ diet at school X than at school Y.
• DThere is less vitamin D in the students’ diet at school X than at school Y.