Answer:
A word used to show the relationship between its object and some other word in the sentence is called a preposition. The correct answer is the first one.
Step-by-step explanation:
A preposition is a word that governs or predicts a noun or pronoun and expresses its relationship to another word or element in the same clause. An example of this can be: "The pencil is under the table". In this example, the word under is a preposition that expresses its relationship with the element in the same sentence (table).