Which of these are Brownian motions?

Let $W$ be a standard Brownian motion. Which of the following processes, defined for $t \ge 0$, are also standard Brownian motions?

• $X_t = 2W_{t/4}$
• $Y_t = \tfrac14 W_{4t}$
• $Z_t = W_{1+t} - W_1$
• $V_t = \sqrt t\,\xi$, where $\xi \sim N(0,1)$ is a single draw fixed for the whole path

For each one that fails, say which property breaks and give a number that shows it.