Among the theories of atherosclerosis, the following is/are true:

a. Fatty streaks in the aorta of children do not predict atherosclerosis or heart attacks

b. Aging induces non-atherosclerotic thickening of the intima

c. T-lymphocytes are present in atheromas 

It is true that fatty streaks in the aorta and coronary arteries of children are found in populations without increased incidence of atherosclerosis or heart attacks. Similarly, aging induces gradual thickening of the intima throughout the arterial tree which is not atherosclerotic. A variety of leukocytes including T-lymphocytes are present in atheromas. The reaction-toinjury hypothesis explains smooth muscle growth in atherogenesis but fails to provide an explanation for lipid accumulation or the monoclonal nature of the atherosclerotic plaque.