A Transplanted Heart Must Be Monitored Periodically to Detect Rejection

A transplanted heart must be monitored periodically to detect rejection. Accordingly, the patient must have periodic tests performed. Which is the most reliable test for detecting cardiac transplantation rejection?

A) Endomyocardial catheter biopsy
B) Cytologic thin needle aspiration biopsy through the pericardium
C) Electrocardiography
D) Serologic testing for T and B cells in blood
E) Testing for troponin I