The correct answer is C. myself.
The sentence “I taught myself to draw” is in the simple past tense. In the simple past tense, the subject and verb agree in number. The subject of the sentence is “I,” which is singular. Therefore, the verb must also be singular. The only singular verb option is “taught.”
The other options are incorrect because they are plural. “Ourselves” and “themselves” are plural pronouns, and “yourself” is a reflexive pronoun. Reflexive pronouns are used to refer back to the subject of the sentence. In the sentence “I taught myself to draw,” the subject is “I,” so the reflexive pronoun “myself” is used.
I hope this explanation is helpful!