Why does Mariam deny knowing fariba when rasheed asks her?

Mariam denies knowing Fariba when Rasheed asks her because she is aware that any association with Fariba might lead to negative consequences for herself. In the oppressive environment she finds herself in, she understands the importance of self-preservation and the need to navigate Rasheed's volatile temperament carefully. By denying the connection, she attempts to protect both herself and Fariba from Rasheed's potential wrath.