What Is the Significance of Gene Mutations in Terms of Protein

What is the significance of gene mutations in terms of protein function and clinical outcome?

A) Changes in gene sequence can alter the shape or function of a protein.
B) Analyzing specific mutations allows researchers to study overall gene function.
C) Gene mutations allow researchers to identify deficient proteins and aid in therapeutic intervention,such as in cystic fibrosis.
D) A and B.
E) All of the above.