Please help with this Fermi Question, thanks!

Tricia uses the Fermi process to estimate the number of buckets of sand she could store in a warehouse. The buckets are shaped like cylinders. The warehouse is shaped like a rectangular prism.

• She estimates the buckets have a height of 15 inches and a diameter of 20 inches.
• She estimates the warehouse is 250 feet long, 80 feet wide, and 20 feet high. Which expression should Tricia use in the process?

​A) \(\frac{7×10^9​}{5×10^4 ​}\)

​B) \(\frac{ 5×10^6}{5×10^3}\) ​ 

C)​ \(\frac{​ 7×10^8​}{​5×10^3 ​}\)​ ​

D) \(\frac{5×10^7}{5×10^4 ​}\)

Thank you so much for all your help in advance!

edit: Guys I have the answer, it's C! So don't worry ;P But thanks!!