Answer:
My grandfather once told me I shouldn't have any regrets in life because I wouldn't remember them when I got to his age anyway.
Explanation:
An anecdote is a usually short account of an interesting, amusing, or biographical incident or event.
An example of an anecdote is the third sentence. The narrator tells us about something that happened to them, about their own experience.
The rest of the sentences don't contain this type of personal information. They are not told from anyone's point of view. They seem like simple, universal statements. This is why we can't say that they are anecdotes and the reason the third option is the correct one.
D. thesis would be my answer
