Final answer:
The set of curves where a curve goes ahead in one direction and then back in the other direction is called compound curves.
Correct option is 4) Compound curves
Step-by-step explanation:
The set of curves described in the question, where a curve goes ahead in one direction and then back in the other, is best described as compound curves. Compound curves are a combination of two or more simple curves that are joined together. For instance, a road may curve to the right and then to the left as it follows the landscape, forming a compound curve. These are useful in engineering and design where a single simple curve is inadequate to navigate the terrain or to serve the intended purpose.
They are not to be confused with straight curves, circular curves, or spiral curves, which are different types of curve geometries used for various purposes.