Why does the author share problems and solutions to organize the article? Pick two choices.

a.
to explain the cause of food storage problems

b.
to explain that there is more than one way to store food

c.
to describe the best way to store food so that it is preserved

d.
to describe how food storage problems can be solved step-by-step

e.
to show that people have been trying to solve this problem for years

f.
to show that food storage is not needed as often as most people would think