What is the formula for computing the internal growth rate $($IGR$)?$

Multiple choice question.

$($ROA $\backslash$times b$)/(1$ ROA $\backslash$times b$)$

$($ROE $\backslash$times b$)/(1$ ROE $\backslash$times b$)$

$($ROA $+$ b$)/(1$ ROA $\backslash$times b$)$

$($ROA $\backslash$times b$)/(1+$ ROA $\backslash$times b$)$