Here is an incorrect Hasse diagram for the partial order. Which of these describes an error in this diagram$-$something that should never occur in a Hasse diagram? Select all that apply.

W

t

X

$$

x is off to the side not connected to anything.

z has only one immediate predecessor, y$.$

t and w are unrelated to each other$-$one should be below the other.

There's a line from z up to u$,$ even though this line would already be guaranteed by transitivity because z is below t and t is below u$.$