Final answer:
The correct answer to the student's question about the three distinct waveforms in a normal ECG is option 4) P wave, QRS complex, T wave, which represent the depolarization and repolarization events of the heart's atria and ventricles.
Step-by-step explanation:
The three distinct waveforms found in a normal electrocardiogram (ECG) are the P wave, the QRS complex, and the T wave. The P wave represents the depolarization of the atria, the QRS complex shows the depolarization of the ventricles, and the T wave indicates the repolarization of the ventricles. It is during the QRS complex that the repolarization of the atria occurs, but this is masked on the ECG. The ventricles begin to contract as the QRS complex reaches the peak of the R wave.
Therefore, the correct answer to the question "What are the three distinct waveforms called that are found in a normal ECG?" is 4) P wave, QRS complex, T wave.