"Existing treatments for MDR-TB are often highly toxic and poorly tolerated, placing patients at high risk of disability and death and curing them only about half the time."What is suggested by the phrase describing MDR-TB treatments as "highly toxic and poorly tolerated"?A)that the treatments are not that serious an issue. B)that the treatments cause minor discomfort for manyC)that the treatments are painful and sometimes deadlyD)that the treatments are often inconveniently administered