Which tool is helpful in visually illustrating activities and decision-making processes?

The correct choice, which is a flowchart, is particularly effective in visually illustrating activities and decision-making processes due to its structured format and clarity. A flowchart uses various symbols to represent different types of actions or steps in a process, such as ovals for starting or ending points, rectangles for instructions or processes, diamonds for decision points, and arrows to indicate the flow of the process. This visual representation allows individuals to easily understand the sequence of steps, the relationships between different aspects of the process, and where decisions must be made.

In contrast, while a Pareto chart focuses on identifying and prioritizing problems or factors by showing them in a bar graph with a cumulative line, it does not illustrate the flow of activities or the decision-making process itself. Similarly, control charts are used primarily in quality control to monitor variations over time and are not designed for mapping out workflows or decision pathways. A histogram, on the other hand, serves to display the distribution of numerical data, providing insights into frequency but lacking the detail needed to map processes or decisions. Hence, a flowchart stands out as the most suitable tool for visually illustrating activities and decision-making processes.