Final answer:
The saw used to cut curved or irregular lines is a coping saw, which has a thin, replaceable blade that can bend or break if pushed too hard.
Step-by-step explanation:
The correct answer to the student's question is a) Coping. A coping saw is specifically designed for cutting curved or irregular lines in materials such as wood or plastic. The frame of the saw holds a thin blade that is easily replaceable, under tension. It is important not to push too hard on a coping saw during its use, as the blade is quite flexible and can bend or break under excessive force.