Which of the Following Is NOT True of Xanthine Derivatives

Which of the following is NOT true of xanthine derivatives?

A) They are used for the prevention and treatment of asthma.
B) They are used for treatment of emphysema, COPD, and bronchitis.
C) They are available in standard and sustained-release forms.
D) They are still the drugs of choice for pulmonary diseases.
E) They cause such side effects as nausea, anxiety, restlessness, gastroesophageal reflux disease (GERD) , tachycardia, and insomnia.