<p>In a 3-dimensional (x, y, z) space, the set of all points
5 units from the x-axis is:</p>
<p>A. a line.
B. 2 parallel lines.
C. a circle.
D. a sphere.
E. a cylinder.</p>
<p>What is the answer?</p>
<p>In a 3-dimensional (x, y, z) space, the set of all points
5 units from the x-axis is:</p>
<p>A. a line.
B. 2 parallel lines.
C. a circle.
D. a sphere.
E. a cylinder.</p>
<p>What is the answer?</p>