PASCAL 2014 Problem 12

Strips are made up of identical copies of pascal 2014 12. Each pascal 2014 12b has length \frac23. Which strip has length 4?

Answer Choices
A. pascal 2014 12a
B. pascal 2014 12b
C. pascal 2014 12c
D. pascal 2014 12d
E. pascal 2014 12e