This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CT and MRI of the Kidney, Subject name: Radiology
Spider leg appearence is seen in: 
Select and explain. 
A. Adult polycystic kidney disease, B. Wilm's Tumor, C. Horse shoe kidney, D. Vesicoureteral reflux
A: Adult polycystic kidney disease
Answer: A: Adult polycystic kidney disease 
Explanation: Ans: A (Adult polycystic kidney disease) Ref: Harrison's online. 18th ed.Explanation:Some important features in Contrast RadiographsSpider leg appearance -- Polycystic kidneyCobra head appearance -- UreteroceleFlower vase appearance of ureters -- Horse shoe kidnexSandy patches -- Schistosomiasis of bladderSoap bubble appearance -- HydronephrosisApple core lesion on barium -- Ca colonClaw appearance on barium enema -- IntussusceptionSaw tooth appearance -- Diverticula of colonBirds beak appearance of esophagus on barium meal -- AchalasiaCork screw appearance of esophagus on barium meal -- Diffuse esophageal spasmString sign of kantor-- Crohn's disseaseThumb printing sign -- Ischemic colitisEGG SHELL CALCIFICATION -- Silicosis. Sarcoidosis. Scleroderma. Histoplasmosis, Amyloidosis, lymphoma following radiotherapy