Question

the contraction phase of the heart is called:
a systole
b diastole
c tachycardia
d cardioversion

Explanation:

The heart has two main phases in its cycle. Systole is when the heart contracts to pump blood out. Diastole is the relaxation phase. Tachycardia refers to a fast - heart rate, and cardioversion is a procedure to restore a normal heart rhythm.

Answer:

A. systole