Determine If the Given Subset Of $R ^ { 3 }$

Multiple Choice

Determine if the given subset of $R ^ { 3 }$ is open, closed, both open and closed, or neither open nor closed. All points $( x , y , z )$ so that $x \geq 1$ , $y < 0$ and $z > 0$

A) Open
B) Closed
C) Both open and closed
D) Neither open nor closed