How Does Seasonality Create Fluctuations in a Firm's Net Income

How does seasonality create fluctuations in a firm's net income over a year?

A) Cost of goods sold will rise and fall along with sales,while administrative and other costs will remain relatively steady.
B) Cost of goods sold will rise when sales fall,and vice versa,while administrative and other costs will remain relatively steady.
C) Cost of goods sold,along with administrative and other costs,will rise when sales fall,and vice versa.
D) Cost of goods sold,along with administrative and other costs,will rise and fall along with sales.
E) Cost of goods sold,along with administrative and other costs,will remain relatively steady.