Which one of the following is not included in Union List?

The correct answer is Public health and sanitation.

Key Points

The Seventh Schedule to the Constitution of India defines and specifies the allocation of powers and functions between Union & States. It contains three lists; i.e. 1) Union List, 2) State List and 3) Concurrent List.
"Public health and sanitation" is on the State list.
Some important subjects of the state list are following
Police
Public health and sanitation
Public order
Betting and gambling
Hospitals and dispensaries
Additional Information

Some important subjects of the Concurrent list are following
Forest
Trade unions
Adoption
Succession
Education
Marriage
Some important subjects of the Union list are following
Army
International Relations
Ports
Railways
Defence
Communication
Highways