Question

using extreme heat or extreme cold to destroy cells in part of the heart which were causing abnormal rhythms...
ablation
congenital
cyanosis

Explanation:

Ablation is a medical - procedure that uses extreme heat or cold to destroy abnormal tissue, such as cells in the heart causing abnormal rhythms. Congenital refers to something present from birth. Cyanosis is a bluish - discoloration of the skin due to lack of oxygen.

Answer:

A. Ablation