Final answer:
The SA and AV nodes are typically supplied by the right coronary artery and the circumflex coronary artery (option B), which are essential in distributing blood to the heart's conduction system and other myocardial regions.
Step-by-step explanation:
The SA (sinoatrial) and AV (atrioventricular) nodes are components of the heart's conduction system and are normally supplied by branches of the coronary arteries. Specifically, the SA and AV nodes are often supplied by the right coronary artery and the circumflex coronary artery.
The right coronary artery runs along the coronary sulcus, supplying blood to the right atrium, parts of the ventricles, and the heart's conduction system. A particular branch of this artery, the posterior interventricular artery or posterior descending artery, supplies the interventricular septum and aspects of both ventricles.
From the left coronary artery, the circumflex artery arises and follows the coronary sulcus, providing blood to areas including the left atrium and ventricle, eventually making connections with branches of the right coronary artery.
Therefore, the correct answer is B: Right coronary, circumflex coronary arteries.