Diane picked up one of the skull casts in her lab and held it up to her visitors to see. She pointed out two rounded gaps in the teeth on either side of the jaw. "This guy smoked a pipe," she explained. "He started on one side and then, when the pipe ground down the teeth, he had to switch to the other."

—Bone Detective: The Story of Forensic
Anthropologist Diane France,
Lorraine Jean Hopping

What happens in this passage that helps show that Diane France is clever?

She speaks in front of visitors to her lab.
She notices two rounded gaps in the teeth of the man’s jaw.
She is chosen to analyze the man’s jaw.
She figures out why the man has two rounded gaps in his teeth.