Explanation:

- In the sentence "Put the fork and knife in the cutlery box," the word "in" is used to indicate the location of the fork and knife.

- Option 1: Preposition

- A preposition shows the relationship between a noun or pronoun and other words in a sentence.

- Words like "in," "on," and "at" are examples of prepositions.

- Option 2: Verb

- Verbs describe an action, state, or occurrence.

- "In" is not performing any of these functions in this sentence.

- Option 3: Conjunction

- A conjunction connects clauses, sentences, or words.

- "In" does not serve this purpose here.

- Option 4: Determiner

- A determiner modifies a noun to specify a certain aspect like quantity or possession.

- "In" is not modifying the noun "cutlery box."

Option 1: Preposition is correct.