Select all the true statements concerning a mapping reduction $f$ that witnesses $A{?}_{m}B$

the mapping reduction involves two languages, A and $B$

$f$ is also a mapping reduction that witnesses $\frac{?}{\text{b}\text{a}\text{r}}(A)\frac{?}{b}{?}_{m}ar(B)$

$f$ is a computable function with domain $B$ and codomain $A$

$f$ is a computable function with domain A and codomain $B$

the informal goal of $f$ is to show that $A$ is "not harder" than $B$

the informal goal of $f$ is to show that $B$ is "not easier" than $A$

If $A$ is decidable then $B$ is decidable

If $A$ is undecidable then $B$ is undecidable

If $A$ is recognizable then $B$ is recognizable

If $A$ is unrecognizable then $B$ is unrecognizable