In RPGN hallmark pathology is-
Distinctive lesions of proliferation are called crescents owing to their shape as they fill Bowman's space. Crescents are formed both by the proliferation of parietal cells and by the migration of monocytes/macrophages into Bowman's space Ref:- Robbins book of basic pathology 10th Ed. pg 532.
Marked enlargement of mesangial tissue
Crescent formation
Thickening of basement membrane
All of the above
Urinary tract