This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid and electrolytes, Subject name: Medicine
Hypercalcemia is seen in- 
Select and explain. 
A. Renal osteodystrophy, B. Vit D resistant rickets, C. Hypoparathyroidism, D. Williams syndrome
D: Williams syndrome
Answer: D: Williams syndrome 
Explanation: People with Williams syndrome (also known as Williams Beuren syndrome or WS) may have problems handling calcium. Most children with WS have blood levels of calcium that are in the high normal range with a smaller fraction of affected individuals (around 15 percent) having very high levels of calcium (hypercalcemia) Ref Davidson 23ed pg 371