21) Female,35 years old. She came to the clinic because of persistent precordial pain for 2 days. Physical examination: frictional sounds can be heard in the fourth rib space on the left side of the...

21) Female,35 years old. She came to the clinic because of persistent precordial pain for 2 days. Physical examination: frictional sounds can be heard in the fourth rib space on the left side of the sternum,which can still be heard after holding the breath. The ECG suggests bow-dorsal downward elevation of the ST seament in the conventionai leads. What is her most likely clinical diagnosis? A Acute myocardial infarction() BVariant angina C Acute pleurisy D Acute pericarditis E Acute pulmonary embolism