Which statement is false?

Costs that are small and unimportant with little impact on profits are called marginal costs.

A marginal cost curve will always intersect the average total cost curve at the minimum average total cost.

Marginal cost is the change in a firm's total cost due to a one unit change in output.

Marginal cost and marginal productivity are inversely related.

Consider the table.

What is the marginal cost of the ninth unit based on the table?

$\backslash$$$340$

$\backslash$$$60$

$\backslash$$$0$

$-\backslash$$$60$