Answer
$12,000~dm^3$
Work Step by Step
We can use the following two conversions.
$1 ~kL = 1000~L$
$1~dm^3 = 1~L$
We can convert $12~kL$ to units of $dm^3$.
$12~kL = \frac{12~kL}{1}\times \frac{1000~L}{1~kL}\times \frac{1~dm^3}{1~L} = 12,000~dm^3$
