Final answer:
The correct preposition to use is 'between' because it refers to something being in the middle of two distinct items. The correct choice is between.
Step-by-step explanation:
A preposition is a short word that is employed in sentences to show the relationship nouns, pronouns or phrases have with other parts within the respective sentences. Prepositions are normally found positioned in the latter part of the sentence, but before a noun or pronoun.
The correct form of the preposition to use in the sentence 'My compact Toyota Yaris is parked (among, between) two full-sized trucks' is between. This is because 'between' is used when referring specifically to one thing being in the middle of two other distinct things. In contrast, 'among' is used when something is in a group or crowd that is not specifically quantified or distinct.