If the colour of the flame obtained by performing the flame test of a substance with the help of platinum wire and concentrated $HCl$ is violet, then the basic radical in the salt is :

The correct option is D potassium
If the colour of the flame obtained by performing the flame test of a substance with the help of platinum wire and concentrated HCl is violet, then the basic radical in the salt is potassium.
Note: In the flame test, barium, potassium, calcium and sodium gives apple green, violet, brick red and golden yellow colors respectively.