Final answer:
The correct option is D. Tubing wrench. A tubing wrench would be the most suitable tool to remove a brake line. Using a pipe over the handle of a wrench can help remove tight bolts, but it should be done with caution.
Step-by-step explanation:
The tool that would most likely be used to remove a brake line is a tubing wrench. A tubing wrench is specifically designed to grip and turn tubes and fittings without damaging them. It has a closed-end design that fits over the brake line securely, providing a firm grip for removal. Using other types of wrenches, such as a box-end wrench or open-end wrench, may not fit properly and could lead to rounding off the brake line fittings, making it difficult to remove.
When encountering a very tight bolt, mechanics sometimes put a length of pipe over the handle of a wrench to increase leverage. This method helps amplify the force applied to the bolt, making it easier to loosen. However, it is important to use caution as it can also be hazardous, as excessive force with a pipe can break the bolt.