Excessive use of ______ and ________ can lead to oral and/or esophageal cancer.

A. NSAIDs and smoking: NSAIDs are not associated with oral or esophageal cancer; they are more linked to gastric mucosal damage. B. alcohol and gum chewing: Gum chewing does not cause cancer; alcohol alone increases risk, but combined with tobacco, the risk increases greatly. C. alcohol and tobacco: Alcohol and tobacco are major risk factors for oral and esophageal cancer due to their carcinogenic effects. D. floss and toothpaste: These are protective oral hygiene practices, not risk factors.