Which sentence lacks parallel structure? a) take him and her to the ballgame. b) i wondered if we should fly, drive, or sail to the florida keys. c) the children played on the swings, dug in the sandbox, and skated. d) i am going to go to the store, shop for ingredients, then cooking will begin.

D) I am going to go to the store, shop for ingredients, then cooking will begin.

Explanation: Parallelism is a literary device that consists in the repetition of the grammatical structure of a word or a phrase, in order to create symmetry in the text. From the given sentences, the one that lacks parallel structure is the corresponding to option D, because there is a lack of consistency in the verbal forms ("I am going to go", "shop" and "cooking"), an example of how we could correct this sentence would be "I will go to the store, shop for ingredients and then I will begin to cook."