Question

Gregor Mendel was the first scientist to use statistics to analyze scientific data. Before Mendel’s experiments, scientists believed that organisms acquired traits from their environment and passed them on to their offspring. After Mendel’s discoveries were accepted, scientists realized that traits passed to offspring were the result of genes being passed from parents to offspring. This is an example of a theory changing because a new scientific method was developed. a law changing because a new scientific method was developed. a hypothesis changing because a new scientific method was developed. an observation changing because a new scientific method was developed.

Answer 1

You can't change a law, because it's just an observation or statement of fact like gravity makes things move toward each other.  
It's not an observation because you can't physically see traits being inherited.
It may be a changing theory or a changing hypothesis.