Final answer:
True. Most gastric ulcers are caused by H. pylori.
Step-by-step explanation:
True. Most gastric ulcers are caused by the gram-negative bacterium Helicobacter pylori. This bacterium is able to tolerate the acidic environment of the human stomach and has been shown to be a major cause of peptic ulcers, which are ulcers of the stomach or duodenum. According to the CDC, approximately two-thirds of the population is infected with H. pylori, but less than 20% have a risk of developing ulcers or stomach cancer.