Math
posted by Kelly .
Janna is creating a multitiered cupcake display for a party. She plans on having 16 cupcakes on each tier.
There is a 1inch space between all cupcakes.
The cupcakes have a uniform width [diameter] of 3 inches.
Each tier will display the cupcakes in either 2 rows of 8, or 4 rows of 4.
There is a complete 2inch border, around the cupcakes, on each tier.
Based on this information, which of the following values could be the length and width of each tier?

a.16 inches by 16 inches
b.15 inches by 15 inches
c.19 inches by 19 inches
d.17 inches by 17 inches