Final answer:
A category of sets of tools in the field of Computers and Technology is known as an Application. Applications are designed for end-users and can range from productivity software to creative suites.
Step-by-step explanation:
A category of tools, or more accurately, a category of sets of tools, is called an Application (Option B). When we talk about an application in the context of computers and technology, we refer to a program or group of programs designed for end-users. Applications can be software like word processors, web browsers, games, or business software. Each application tends to serve a specific purpose for the user and includes a set of tools that enable tasks to be completed. Examples include the Microsoft Office Suite, which is an application containing tools like Word, Excel, and PowerPoint for productivity tasks, or Adobe Creative Cloud, which includes tools for different types of digital creation tasks like Photoshop and Illustrator.
However, it's important to note that the other options provided relate to different aspects of technology and problem-solving: A Toolkit is a set of tools, often used in the context of software development or repair; an Algorithm is a step-by-step procedure used for calculations and data processing; and a Protocol is a set of rules that govern data exchange between computers.