Using the following pruning table, which tree is the best$-$pruned tree?

Level CP Num Splits Rel Error X Error X Std Dev

$10\mathrm{.}5001\mathrm{.}001\mathrm{.}170\mathrm{.}050735$

$20\mathrm{.}4410\mathrm{.}500\mathrm{.}730\mathrm{.}061215$

$30\mathrm{.}0020\mathrm{.}060\mathrm{.}100\mathrm{.}030551$

Multiple Choice

Level $3$

Additional Levels needed to identify best$-$pruned tree.

Level $1$

Level $2$