Answer: Direct Object
Explanation:
Noun phrases are words that together can function as a noun. In this case that would be my favorite book.
Nouns and noun phrases that are worked on by the verb in a sentence are considered to be direct verbs. In other words, the verb's actions directly affect the direct objects.
For instance, I am answering this question on Brainly. The question is the object that is affected directly by the verb answering.
In the sentence: I made sure to bring my favorite book to camp with me, my favorite book is directly affected by the verb as it is the one being brought so it is a direct object.