Flavouring compound for butter is

Answer: Option B

Flavouring compound for butter is Diacetyl.
Diacetyl is also the primary flavor compound in starter cultures and distillates which are used in producing cultured butter. It is a volatile yellow liquid ketone with a cheese-like smell.
It is a naturally occurring substance that gives butter its characteristic flavor and aroma and is often a component of artificial flavoring formulations.