Argentina is in South America and the US is in North America
The answer is este it is used as a masculine adjective where as esto is a demonstrative pronoun for masculine and feminine nouns
Answer:
Profesora: <u>Hola</u> Eric.
Eric: <u>Hola</u> profesora! ¿Como <u>le va?</u>
Profesora: Me va <u>muy bien</u> ¿Y a ti, como <u>te va</u>?
Eric: Me va <u>bien</u>.
That's it, have a good day.