Which of the following represent the commonest variation in the arteries arising from the arch of aorta?

Which of the following represent the commonest variation in the arteries
arising from the arch of aorta?
a) Absence of brachiocephalic trunk
b) Left vertebral artery arising from the arch
c) Presence of retroesophageal subclavian artery
d) Left common carotid artery arising from brachiocephalic trunk

Correct Answer - D
Most common anomaly of the aortic arch seen in 10-20% individuals is characterized by the
origin of the left common carotid artery from the brachiocephalic (innominate) trunk.
Other common anomalies include: A four vessel arch with separate origins for the right
common carotid and right subclavian arteries (2.5%), Origin of the left vertebral artery
directly from a four vessel aortic arch typically between the ostia of the left common carotid
and subclavian arteries ( 2.4- 5.8%).