Three real numbers x, y, z are chosen randomly, and independently of each other, between 0 and 1 , inclusive. What is the probability that each of x-y and x-z is greater than -\frac{1}{2} and less than \frac{1}{2} ?
Answer Choices
A. \frac{3}{4}
B. \frac{7}{12}
C. \frac{1}{4}
D. \frac{1}{2}
E. \frac{2}{3}