A cria is a young llama whose sex is not specified by the term itself. The correct answer is C, indicating that the cria is young, but its sex is not determined.
The term cria is used to describe a young llama that is still nursing or dependent on its mother.
The term does not specify the sex of the animal, hence the correct answer to what is the age and sex of the animal that Miley is tending to on the llama farm is C. young but sex not determined.
Even though the narrative provides information about a goat named Maisie giving birth to a male and introduces the concept of the librito, it does not directly indicate the age or sex of the cria Miley is working with.