What is$/$are the reason$($s$)$ why we may have a relational model with data redundancy?

Group of answer choices

$($b$)$ a relational model with data redundancy may result from an existing database poorly designed by others

both $($a$)$ and $($b$)$

if we transform the ER model into a relational model correctly, we won't have data redundancy

$($a$)$ a relational model with data redundancy may result from a poorly designed E$-$R model