A game board consists of 64 squares that alternate between blank and colored. The figure below shows square P in the bottom row and square Q in the top row. A marker is placed at P. A step consists of moving the marker onto one of the adjoining blank squares in the row above. How many 7-step paths are there from P to Q?
Answer Choices
A. 28
B. 30
C. 32
D. 33
E. 35