<h2>Right answer: ¿Cómo sos?
</h2>
The <em>"voseo"</em> is used as the main form of the <u>second person of the singular</u> tú (you) in the River Plate Spanish of Argentina, Uruguay and eastern Bolivia, and in the Paraguay's spanish.
Nevertheless,<em> "vos" </em>is also used in <u>some regions </u>of: Costa Rica, Bolivia, Chile, Peru, Ecuador, Colombia, Venezuela, Panama, Nicaragua, Honduras, El Salvador, Guatemala, Mexico and Cuba. Although, this is not used in all the countries of Latin America or all its regions.
It should be noted that this <u>linguistic phenomenon within the Spanish (Castilian) language</u> in which the pronoun <em>"vos"</em> is used along with certain particular verb conjugations instead of using the pronoun "tú" in situations of familiarity.
For example, with the verb ser (to be) conjugated with <u>the second person of the singular</u>, instead of asking:
¿(Tú) Cómo <u>eres</u>?
What are you like?
Eres is changed to sos, having the same meaning:
¿ (Vos) Cómo <u>sos</u>?
What are you like?