What is the main piece of evidence supporting the theory of seafloor spreading? Fossils of plants and animals along the ocean floor

Volcanic activity along the Ring of Fire

Glacial scratches on the seafloor

Alternating magnetic pattern in the rocks of the ocean floor

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost