The following is Corporation A's contribution format income statement for last month:

Sales

$1,000,000

Less: variable expenses

700,000

Contribution margin

300,000

Less: fixed expenses

180,000

Operating income

$120,000

The company has no beginning or ending inventories. A total of 20,000 units were produced and sold last month.

What is the company's contribution margin ratio?

Select one:

a.250%

b.30%

c.70%

d.150%