What is an emulsion?

An emulsion is defined as a mixture of two immiscible liquids, typically oil and water, where one liquid is dispersed in the other in the form of small droplets. In this case, option B accurately describes an emulsion, emphasizing the combination of oily and watery substances.

In the context of emulsions, they require certain stabilizing agents, known as emulsifiers, to prevent the two phases from separating. This process is essential in various fields, including food science, pharmaceuticals, and cosmetics, where maintaining a stable mixture is crucial for effectiveness and usability.

The other choices do not correctly represent the nature of an emulsion. A solution where both substances are miscible implies complete solubility rather than a mixture where different phases exist. A drug in an alcohol base refers specifically to a solvent system and does not pertain to emulsions. Finally, a suspension of drugs in sugar solution suggests solid particles dispersed in a liquid, which again does not involve the characteristics of an emulsion. Thus, option B provides the most accurate depiction of what constitutes an emulsion.