The answer to the question is b- Violet ring.

The Bradshaw test is a chemical test used to detect the presence of bile salts in a sample. Bile salts are produced by the liver and are important in the digestion and absorption of fats in the small intestine. The presence of bile salts in urine, blood, or other bodily fluids can indicate liver disease or other conditions affecting bile production.

The Bradshaw test involves mixing the sample with a reagent containing sulfuric acid and cane sugar. If bile salts are present, they will react with the sugar to produce a colored ring at the top of the mixture. The color of the ring can vary depending on the type of bile salt present.

A positive Bradshaw test is indicated by the appearance of a violet ring at the top of the mixture. This color is produced by the reaction of taurocholate, a type of bile salt, with the sugar in the reagent. Other bile salts may produce different colors, such as a red ring for glycocholate or a greenish-blue precipitate for deoxycholate.

Overall, the Bradshaw test is a simple and reliable method for detecting the presence of bile salts in a sample. It can be useful in diagnosing liver disease and monitoring treatment progress.