Most common cause of thoracic aortic aneurysm is

(A) AtherosclerosisDISEASES OF THE AORTA: ETIOLOGY & ASSOCIATED FACTORSAortic aneurysmAortic occlusion* Atherosclerosis* Atherosclerosis* Cystic medial necrosis* Thromboembolism* Tuberculosis* Aortitis* Syphilitic infection* Syphilitic aortitis* Mycotic infection* Rheumatic aortitis* Rheumatic aortitis* Takayasu's arteritis* Trauma* Giant cell arteritis* Aortic dissection * Cystic medial necrosis * Systemic hypertension * Atherosclerosis * Takayasu's arteritis * Giant cell arteritis