Ascientist has been working for 15 years to develop a new type of plastic material, but she has not yet been successful. which of the following best explains why her work is still a success?

The biggest reason for that her work is a success is because new ideas often develop from unsuccessful experimentation.
The scientific process not only relies on proper experimental methods and determination, but it also is dependent on the failures of the experiments of scientists. When experiments fail, other scientists obtain a guideline of what to do and what not do. This improves their own experiments and helps them move forward.