The correct option is B
- A streamlined body is a shape that reduces friction drag between a fluid, such as air or water, and an object moving through it.
- Drag is a force that slows movement; friction drag is a subset of drag.
- It happens when the fluid closest to the object stick to its surface, exerting a force that opposes the motion of the object.
- Many animals, including birds and dolphins, as well as many machines, including airplanes and submarines, have streamlined bodies to reduce friction drag as they move through air or water.
Hence, Option(B) is correct.