A 60 year old female with polydyspia. Water deprivation test was performed and the values obtained are as follows : (Baseline : Na+-139 mEq, K+-3.9 mEq, osm. plasma-274/L osm, urine-150 mosm.After vasopression : Na+-142)mEq, K+-3.9 mEq, plasma osm 271 mosm/L, urine osm-489 mosm/L). Diagnosis is -

A 60 year old female with polydyspia. Water deprivation test was perfo

1.	A 60 year old female with polydyspia. Water deprivation test was performed and the values obtained are as follows : (Baseline : Na+-139 mEq, K+-3.9 mEq, osm. plasma-274/L osm, urine-150 mosm.After vasopression : Na+-142)mEq, K+-3.9 mEq, plasma osm 271 mosm/L, urine osm-489 mosm/L). Diagnosis is -
A.	Cranial diabetes insipidus
B.	Psychogenic polydypsia
C.	Nephrogenic diabetes insipidus
D.	SIADH
Answer» B. Psychogenic polydypsia