Final answer:
Sentence 3 should be changed to reflect the chef teaching his students about fine food.
Step-by-step explanation:
The sentence in question focuses on the chef teaching his students about food. Sentence 3 can be changed in tone by choosing option D, which says 'The chef taught his students about fine food.' This option maintains a professional and informative tone, while also accurately reflecting the topic being discussed in the paragraph.
Learn more about Tone of sentence 3 in a paragraph about a restaurant