Which numbers are necessary to solve this problem?

A fence company has been in business for 18 months. It makes 450 white posts and 200 beige posts a day.

How many posts will the company make in 4 days?

A.
450 white posts, 200 beige posts

B.
450 white posts, 200 beige posts, 4 days

C.
18 months, 450 white posts, 200 beige posts

D.
18 months, 450 white posts, 200 beige posts, 4 days