What pattern does an ECG gather information on a heartbeat from?

The correct answer is D because an ECG, or electrocardiogram, specifically measures electrical activity in the heart during different phases of the heartbeat. The letters P, Q, R, S, and T correspond to distinct waves observed in a standard ECG.

The P wave represents atrial depolarization, which is when the atria contract to pump blood into the ventricles. Following this, the QRS complex corresponds to ventricular depolarization, showcasing the electrical activity as the ventricles contract. Finally, the T wave indicates ventricular repolarization, marking the period when the ventricles prepare for the next contraction.

Each of these components is vital for understanding the heart's rhythm and electrical conduction system, making P, Q, R, S, and T essential in interpreting an ECG reading. The other patterns do not accurately relate to the stages of a heartbeat or the terminology used in cardiology and ECG analysis.