Desmond builds a set of towers out of blocks. The table shows the number of blocks in each tower.
Tower #
1 2. 3. 4. 5
Number of blocks
5 10 20 40 80
Which explicit formula correctly represents the number of blocks, an, in terms of the tower number, n?
O A. an = n + 80
O B. an = 2n + 5
OC. an = 5(2)-1
OD. an = 10(5)