V61-03

A discovery made by two Australian researchers, Barry Marshall and John Warren, revolutionized the scientific community's understanding of peptic ulcer disease and transformed the illness from a chronic, frequently disabling condition to one that can be cured by a short regimen of antibiotics.
In 1981, the two researchers first began to work together. Their discovery came about after Warren had observed bacteria in the lower part of the stomach of patients, which contradicted the long-held belief that bacteria could not survive in the acidic stomach environment. Warren also noticed that signs of inflammation were always present close to the bacteria. While conducting further studies on more patients, Warren and Marshall found H. pylori bacteria present in almost all patients with stomach inflammation or ulcers in the stomach. The two hypothesized that there was a causal link between H. pylori and ulcers, and that ulcers were not caused by stress, as previously thought. In order to support their controversial claims, they experimented on animals, and when this turned out to be unsuccessful, Marshall took it upon himself to be his own guinea pig. After verifying that he did not already have H. pylori in his stomach, Marshall drank a concoction made from cultured bacteria. Within a few days, he came down with gastritis, and H. pylori were found in his inflamed stomach; he was then cured with the help of antibiotics.
The researchers' findings were so contentious that it took ten years for their work to be accepted. Many researchers tried to disprove their findings, but failed to do so. Despite this, numerous scientists and doctors remained doubtful and refused to believe that any bacteria could live in the acidic environment of the stomach. According to Marshall, the pharmaceutical industry also had a role in preventing their bacteria theory from gaining traction. At the time, the most common treatment for ulcers was antacids, which required constant use, since the symptoms would return immediately after patients stopped taking them. Hence, the notion that ulcers could be permanently cured by taking antibiotics was highly unappealing to the pharmaceutical companies. By 1994, however, the evidence was overwhelming, prompting a change in the treatment of ulcers and establishing antibiotics as the standard approach. Finally, in 2005 Warren and Marshall received the praise they so clearly deserved, winning the Nobel Prize in Physiology or Medicine for their innovative work.

It can be inferred from the passage that Warren and Marshall’s conclusion is based on which of the following claims?

A. Animals cannot be infected with H. pylori bacteria.
B. H. pylori bacterial infection is not caused by stress.
C. Bacterial infection can be cured with antibiotics.
D. Experiments that had been conducted thus far on the cause of ulcers were not accurate enough.
E. Pharmaceutical companies wanted to hide the real cause of ulcers.