The word that correctly completes the conversation is:
Son.- Alejandro: ¿De dónde vienen Gloria y Gabriela?
- Ricardo: Gloria y Gabriela son peruanas.
Explanation:
The translation of the conversation given is:
- Alejandro: Where do Gloria and Gabriela come from?
- Ricardo: Gloria and Gabriela are Peruvian.
Although a response is usually started with the format that has the question asked, in Spanish, it is quite usual to change that sense a bit, as long as the sense of the answer is preserved, as you can see in the conversation where do they come from? The answer can be by mentioning nationality, as in this case, using the verb "ser" in its conjugated form "son", because it refers to a plural noun since in case of being singular it could respond with the conjugated form "es", the option "vienen" is not taken into account because the next word is a nationality, for using that conjugated verb, the next word should be the country, For example:
Gloria y Gabriela son de Perú.