Answer:
The verb form that correctly completes the conversation is:
- <u><em>Estudiando</em></u>.
- <em>Alex:</em><em> ¿Qué estás haciendo, Lupe?
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<em>- Lupe:</em><em> Yo estoy </em><em><u>estudiando</u></em><em> matemáticas.</em>
Explanation:
The translation of the conversation is:
- Alex: What are you doing, Lupe?
- Lupe: I am <u>studying</u> mathematics.
When it is required to mention actions that are being executed at the moment in question, <u>continuous-time or progressive tense</u> is used, whose characteristics in Spanish are:
- It contains some form of the verb <em>"estar"</em> as <em>estoy, estás, está, estamos, están</em>.
- The main verb finishes in <em>"ando"</em> or <em>"endo."
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Since all options are conjugations of the verb to study conjugates for different people or personal pronouns and only one option in continuous time, the correct option is "<u>estudi</u><u>ando</u>" which ends in <em>"ando."</em>
