Answer: D) The pool picnic’s entertaining games and delicious food should not be missed.
Explanation: The tone of a text or sentence is the author's or speaker's attitude towards the audience, the subject or even the characters of the text. There are many different kinds of tones, like: positive, negative, objective, sad, angry, etc. From the given options, the sentence that has a persuasive tone is the corresponding to option D, because by saying that the pool picnic should not be missed, it is trying to convince the audience.