WHAT DOES THE WORD “WHICH” IN THE FOURTH PARAGRAPH REFER TO

39: - DE THI THU DAI HOC BAM SAT DE THI TNTHPTQG NAM 2017 CO DAP AN
Tiếng Anh DE THI THU DAI HOC BAM SAT DE THI TNTHPTQG NAM 2017 CO DAP AN

39: What does the word “which” in the fourth paragraph refer to?

A. Foods B. Chambers C. Things D. Vegetables