Passage OneQuestions 61 to 65 are based on the following passage:Adverse (不良的) drug reactions may cause the deaths of over 100,000 US hospital patients each year, making them a leading cause of death nationwide, according to a report in the Journal of the American Medical Association.“The incidence (发生率) of serious and fatal adverse drug reactions (ADRs) in US hospitals was found to be extremely high,” say researchers at the University of Toronto in Ontario, Canada.They carried out an analysis of 39 ADR-related studies at US hospitals over the past 30 years and defined an ADR as “any harmful, unintended, and undesired effect of a drug which occurs at doses (剂量) used in humans for medical treatment.”.An average 6.7% of all hospitalized patients experience an ADR every year, according to the researchers. They estimate that “in 1994, overall 2,216,000 hospitalized patients had serious ADRs, and 106,000 had fatal ADRs.” This means that ADRs may rank as the fourth single largest cause of death in America..The control of ADRs also means spending more money. One US study estimated the overall cost of treating ADRs at up to $4 billion per year.Dr. David Bates of Brigham and Women’s Hospital in Boston, Massachusetts, believes that healthcare workers need to pay more attention to the problem, especially since many ADRs are easily preventable. “When a patient develops an allergy (过敏症) or sensitivity, it is often not recorded,” Bates notes, “and patients receive drug to which they have known allergies or sensitivities with disturbing frequency.” He believes special computerized systems – still work-in-progress at many of the nation’s hospitals – should help cut down the frequency of these types of errors. What does the word fatal (Para. 4) mean in the passage

A. Resulting in death.
B. Lucky
C. Leading to happiness.
D. Worried