Explanation:

Detergents are synthetic cleaning agents, and their primary active components are often sulphonates. Specifically, many common detergents are sodium salts of long-chain alkylbenzenesulfonic acids or other sulphonic acid derivatives. These sulphonate groups provide the hydrophilic (water-loving) part of the detergent molecule, allowing it to interact with water, while the long hydrocarbon chain provides the hydrophobic (water-fearing) part that interacts with grease and dirt. Bicarbonates (Option A) like sodium bicarbonate are used as mild abrasives or deodorizers but are not the primary cleaning agents in detergents. Bismuthates (Option B) are compounds containing bismuth and oxygen, not typically found in detergents. Nitrates (Option D) are salts of nitric acid and are not characteristic components of detergents for cleaning purposes. Therefore, sulphonates are the key active ingredients in many detergents.