The answer is C. abiertas. Because ventanas is feminine, as the word abiertas. Also, the words in A and B doesn't exist. And D is masculine so it can't be the answer.
Answer : C) Las ventanas están abiertas.
Explanation : The subject in this sentence is "Las ventanas", that is a plural, feminine noun, so the last word must agree in gender and number. Abiertas.
[tex]\textit{\textbf{Spymore}}[/tex]
