GAUSS7 2013 Problem 20

Toothpicks are used to make rectangular grids, as shown. Note that a total of 31 identical toothpicks are used in the 1\times10 grid. How many toothpicks are used in a 43\times10 grid?

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Answer Choices
A. 913
B. 860
C. 871
D. 903
E. 946