Final answer:
The correct verb form is 'encuentro'
Step-by-step explanation:
The correct verb form to fill in the blank in the given sentence is option OA. 'encuentro'. In the sentence, the subject 'yo' (which means 'I' in Spanish) requires the verb form 'encuentro' to match the first person singular form in the present tense. The correct sentence would be 'Necesito mi tarea de matemáticas, y no la encuentro'.
Learn more about Spanish verb forms