22. What can be inferred from the passage?

(A)Phytoncides are used to grow forest plants and prevent tree cancer.
(B)Phytoncides may kill most of human natural cells after 30-day trips in Japan.
(C)Phytoncides fight against our health by providing bacterial and fungal qualities.
(D)Phytoncides are chemicals that trees produce to protect themselves from diseases.

Exposure to forests boosts our immune system. While we breathe in the fresh air, we breathe in phytoncides, airborne chemicals that plants give off to protect themselves from insects. Phytoncides have antibacterial and antifungal qualities which help plants fight disease. 
接觸森林可以增強我們的免疫系統。 當我們呼吸新鮮空氣時，我們吸入植物殺菌素，植物釋放的空氣中的化學物質可以保護自己免受昆蟲侵害。 植物殺菌素具有抗菌和抗真菌的特性，可以幫助植物抵抗疾病。
從文章中可以推斷出什麼？

（A）殺菌劑用於種植森林植物和預防樹木癌症。

（B）在日本旅行30天后，殺菌劑可能會殺死大多數人類天然細胞。

（C）殺菌劑通過提供細菌和真菌的特性來對抗我們的健康。

（D）殺菌劑是樹木為了保護自己免受疾病侵害而產生的化學物質。