Answer:
The correct answer is intensive pronoun.
Step-by-step explanation:
Intensive pronouns, which include myself, yourself, himself, herself, itself, ourselves, yourselves, themselves, are used to add emphasis to the subject. that is why they are usually found after the noun or pronoun that they are emphasizing or modifying.
They are not essential to a sentence’s basic meaning, that is to say, they can be removed from the sentence and it will still make sense.
Bearing the described above, it could be said that in the sentence provided: "Thomas Jefferson himself worked on a draft of the document." the word "himself" corresponds to an intensive pronoun, since it is right after the noun "Thomas Jefferson" and it could be remove it from the sentence and it will still make sense.