Step 1: The question asks for the profession of Mr. Gessler, the main character in the story "Quality".
Step 2: The entire story revolves around his profession and his unwavering dedication to it.
Step 3: Mr. Gessler was a traditional German 'shoe-maker' (or boot-maker) in London who created high-quality, handmade boots. His profession is central to the story's theme of quality versus commercialism. The marked answer (C) is incorrect.