There might be some rules that can be applied to Spanish grammar.
*Subject and verb should agree on number. For example, Ella esta escribiendo.
* Adjectives and noun should agree on gender and number. La casa es hermosa. Los arboles son pequeños.
pagina, boleto, ventanas, maletas, personas, el tren, terminal, conductor, and vias de tren
Answer:
Las
Explanation:
"Las" would make the most sense because the people Ernesto is referring to are all "sisters (hermanas)" aka all women
Whenever there is a group of women being pointed out, you have to use the feminine term for "them" which is "Las"
"Los" would work only if there was a male or males among them or only a group of males in general
"Lo" and "La" are singular but "hermanas" is more than one sister therefore those would be incorrect also