Final answer:
The Pen tool is the correct choice for drawing free form curved lines in graphic design software, offering precision in creating complex shapes and paths.
Step-by-step explanation:
The tool that can draw free form curved lines is the Pen tool. The Pen tool is utilized for creating custom shapes and paths with precision by adding and manipulating anchor points. Unlike the Connector, Shape, or Text tools, the Pen tool gives you the ability to create complex and detailed paths that can consist of straight lines and curves. While the information about drawing an ellipse with pins and a loop of string is a method for creating a precise geometric shape, it demonstrates the concept of manipulating a tool to create a specific form, similar to how the Pen tool can be used to define and control curves in graphic design software.