Which of the following comes under Union List of 7th schedule of the Indian constitution ?

Establishment of standards of weight and measure 

The correct answer is Option 4 - Establishment of standards of weight and measure

Establishment of standards of weight and measure falls under the Union List of the 7th Schedule of the Indian Constitution.
Public Health and sanitation, Hospitals and dispensaries fall under the State List.
Public order is partially under the Union List (for armed forces) and partially under the State List (for maintaining civil order).