A coin is tossed thrice. Let $X$ be the event that head occurs in each of the first two tosses. Let $Y$ be the event that a tail occurs on the third toss. Let $Z$ be the event that two tails occur in three tosses. Based on the above information, which one of the following statements is $TRUE$?
- $X$ and $Y$ are not independent
- $Y$ and $Z$ are dependent
- $Y$ and $Z$ are independent
- $X$ and $Z$ are independent