Pick the answer closest to the typical limits on the mortgage payment$-$to$-$income ratio?

Question $1$ options:

$30\%$ front$-$end, $40\%$ back$-$end

$40\%$ front$-$end, $30\%$ back$-$end

$60\%$ front$-$end, $80\%$ back$-$end

$80\%$ front$-$end, $60\%$ back$-$end

$45\%$ front$-$end, $45\%$ back$-$end