Cardiac cells can withstand ischemic conditions for 20 minutes before irreversible cell injury occurs:

Choice A reason: H. pylori infection is a well-known cause of duodenal ulcers. This bacterium damages the protective lining of the stomach and duodenum, leading to inflammation and ulceration. It is one of the most common causes of peptic ulcers worldwide.
Choice D reason: Nonsteroidal anti-inflammatory drugs (NSAIDs) are another primary cause of duodenal ulcers. These medications can irritate the stomach lining and increase acid production, leading to ulcer formation. Long-term use of NSAIDs is particularly associated with this risk.
E reason: Chronic alcohol (ETOH) abuse can also lead to duodenal ulcers. Alcohol irritates the stomach lining and increases acid production, which can contribute to the development of ulcers. Additionally, alcohol abuse can impair the healing process of existing ulcers.
Choice B reason: Side effects of antibiotics are not typically associated with the primary causes of duodenal ulcers. While antibiotics can cause gastrointestinal disturbances, they are not a common cause of ulcer formation.
Choice C reason: Trauma is not a primary cause of duodenal ulcers. While severe physical stress or injury can lead to stress ulcers, these are different from the typical duodenal ulcers caused by H. pylori infection, NSAIDs, or chronic alcohol abuse.

Choice A reason:
While decreased cerebral blood flow can contribute to various neurological conditions, it is not the primary cause of hepatic encephalopathy. Hepatic encephalopathy is primarily associated with liver dysfunction rather than cerebrovascular issues. Thus, this choice is incorrect.
Choice B reason:
Impaired ammonia metabolism is the primary cause of hepatic encephalopathy. When the liver is unable to adequately convert ammonia to urea due to chronic liver disease, ammonia accumulates in the bloodstream. This leads to toxic effects on the brain, resulting in the symptoms of hepatic encephalopathy. Therefore, this choice accurately reflects the underlying pathophysiology of the condition.
Choice C reason:
Hyperbilirubinemia and jaundice are common in liver disease but are not the primary causes of hepatic encephalopathy. These conditions result from impaired bilirubin metabolism and do not directly lead to the neurological manifestations seen in hepatic encephalopathy. Therefore, this choice is incorrect.
Choice D reason:
Fluid and electrolyte imbalances can occur with chronic liver disease but are not the primary cause of hepatic encephalopathy. While they may exacerbate the condition, the main issue is the accumulation of ammonia due to impaired liver function. Hence, this choice is incorrect.