Final answer:
Taxol (A) is the substance that provides protection to trees in the Pacific Northwest and also has the potential for use in treating cancer.
Step-by-step explanation:
The substance that provides protection to trees in the Pacific Northwest and also has the potential for use in treating cancer is Taxol (A).
Taxol is a powerful anticancer drug that was originally extracted from the Pacific yew tree. It is used to treat various types of cancer, including breast, ovarian, and lung cancer. Taxol works by disrupting the process of cell division, effectively preventing the growth and spread of cancer cells.
Although taxol can be extracted from the yew tree, it can also be synthesized in the laboratory, making it more accessible for medical use.