AMC 10B 2014 Problem 5

Doug constructs a square window using 8 equal-size panes of glass, as shown. The ratio of the height to width for each pane is 5: 2, and the borders around and between the panes are 2 inches wide. In inches, what is the side length of the square window?

Answer Choices
A. 26
B. 28
C. 30
D. 32
E. 34