Prefixes are letters that we add to the beginning of a word to make a new word with a different meaning.
Prefixes can, for example, create a new word opposite in meaning to the word the prefix is attached to.
They can also make a word negative or express relations of time, place, or manner.
Here, in the given question the 'auto' prefix is correct. Because adding 'auto' before 'autobiography' will make a meaningful word. The meaning of it as follows:
Autobiography: a book about a person's life, written by that person
Example: Tony Blair's autobiography was a bestseller.
Therefore, as per the points mentioned above, we find that the correct answer is Option 2.