Answer:
The sentence grammatically correct is:
C) Nosotros somos de Argentina.
Explanation:
The verb "ser" in Present Simple Tense and depending on the personal pronoun, has the conjugation that I write below:
How the personal pronoun used in the sentence is "nosotros," the right conjugation that applies for that noun is "somos", so, the correct option is "Nosotros somos de Argentina."