Use the following table to answer this question, which provides information on the production of a product that requires one variable input.

$\backslash$table$[[$Input$,\backslash$table$[[$Total$],[$Product$]]],[0,0],[10,200],[20,600],[30,720],[40,820],[50,900],[60,980]]$

The marginal product of the $30$ th input item is

Multiple Choice

$120.$

$12.$

$200.$

$24.$