One effect that theophylline, nitroglycerin, isoproterenol, and histamine have in common is (LQ)
|A||Direct stimulation of cardiac contractile force|
|C||Increased gastric acid secretion|
Theophylline does not cause headache. Nitroglycerin does not increase gastric acid secretion. Isoproterenol does not cause either. Histamine may cause all of the effects listed.