Let a computer program generate only the digits 0 and 1 to form a string of binary numbers with probability of occurrence of 0 at even places be $$\frac{1}{2}$$ and probability of occurrence of 0 at the odd place be $$\frac{1}{3}$$. Then the probability that 10 is followed by 01 is equal to:

A

$$\frac{1}{18}$$

B

$$\frac{1}{3}$$

C

$$\frac{1}{6}$$

D

$$\frac{1}{9}$$