The verb, ser, is in the singular el/ella/usted tense, meaning that the subject is only one person or thing. This eliminates the two middle choices, as they are multiple people.
Next, the adjective. Alto is in the masculine form, so Maria, as it is a girl name, is also able to be eliminated.
Yo (veo, miro, observo) la televisión en la cabina. The three answers would all be correct, but the one that is most used is miro. The three words mean see (veo), look (miro), and observe (observo).
