Answer:
The word or phrase that best reveals the author's tone towards his uncle's advice is "proverb of universal application"
Step-by-step explanation:
The phrase "proverb of universal application" makes the words of his uncle the most important thing in this paragraph, besides highlighting it, the author also shows the intention of the words he many times heard coming out from his uncle's mouth, the other options describe little parts of the general point but not the whole idea.