B

Microaneurysms form on capillaries that course through the deep inner retinal plexus, which lies within the inner nuclear layer; histologic and OCT studies show that the majority of early diabetic microaneurysms originate in this layer rather than in the outer retina or RPE [Moore et al., 1999, PMID 10227670; Horii et al., 2010, PMID 20855054].