Elon Musk is best known for his leadership role at Tesla, Inc., where he has served as CEO and product architect. Tesla is a pioneering company in the development of electric vehicles, battery energy storage, and clean energy solutions. While Musk has also founded and led other companies (like SpaceX, Neuralink, and The Boring Company), the name most closely and popularly associated with him in the public domain is Tesla.
The other options are incorrect:
- (A) Google: Founded by Larry Page and Sergey Brin, not Musk.
- (B) GM: General Motors is a historic American automaker, unrelated to Musk.
- (C) GD: Not relevant here.
- (E) Apple: Founded by Steve Jobs, Steve Wozniak, and Ronald Wayne.
Thus, the correct association is:
\[
\boxed{\text{Tesla}}
\]