FERMAT 2012 Problem 15

Oranges are placed in a pyramid-like stack with each layer completely filled. The base is a rectangle that is 5 oranges wide and 7 oranges long. Each orange, above the first layer, rests in a pocket formed by four oranges in the layer below, as shown. The last layer is a single row of oranges. The total number of oranges in the stack is

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Answer Choices
A. 53
B. 80
C. 82
D. 85
E. 105