A tourist begins a city stroll at an intersection. He walks north one block and then flips a coin. If the coin shows heads, he turns right; if it is tails, he turns left. In all, he walks a total of four blocks, flipping the coin at each corner to decide which way to turn. What is the probability that he ends at the starting point?

W) 1/8

X) 1/4

Y) 1/3

Z) 1/2
X) 1/4