In which of the following cases, benedicts test comes false positive
Option 4

In case of Alkaptonuria, homogentisic acid is accumulated in and gets excreted in urine. It is  a reducing substance and hence gives false positive Benedict's test.

Option 1, 2 & 3:

Give true positive Benedict's test.
Galactose, Glucose are reducing sugars.
Urine sample of patient with classical galactosemia
Urine sample of 10 year old child with Type IDM.
Urine sample of 50 year old male with Type II DM
Urine sample of patient with alkaptoncuria