Consider an experiment of tossing a coin repeatedly until the outcomes of two consecutive tosses are same. If the probability of a random toss resulting in head is \( \frac{1}{3} \), then the probability that the experiment stops with head is:
\( \frac{1}{3} \)
\( \frac{5}{21} \)
\( \frac{4}{21} \)
\( \frac{2}{7} \)
