This question is incomplete. Here's the complete question.
Read A Dead Woman's Secret
By Guy de Maupassant
1880
How do the siblings' reactions to their mother's  letters contribute to the theme of the text?
The siblings are shocked, contributing to the theme that  people are not always as they seem.
The siblings are angered after learning about their real  father, contributing to the theme that it is best to be  honest with others.
The brother condemns their mother but the sister  sympathizes with her, contributing to the theme of  forgiving loved ones.
The siblings are shocked but still watch over their  mother, contributing to the theme that it is best to be  loyal to family.
Answer: The siblings are shocked, contributing to the theme that  people are not always as they seem.
Explanation:
Through the letter, the siblings find out that their assumed virtuous mother had at least one love affair. After being raised by the now-deceased woman, who inculcated them a strict code of morality and religiosity to such extent that Marguerite had become a nun and the son a flawless magistrate, this discovery makes them furious, and they angrily leave her. 
 
        
             
        
        
        
I think it’s both, but probably leaning more towards ethos.
 
        
                    
             
        
        
        
The first choice would be the correct answer it makes more sense and goes along with the story