To rotate a point \((x, y)\) around the origin by \(270^\circ\) counterclockwise, you can use the following rotation formula:
\[ (x', y') = (y, -x) \]
For the point \((5, 8)\):
- Set \(x = 5\) and \(y = 8\).
- Apply the rotation formula:
- \(x' = y = 8\)
- \(y' = -x = -5\)
Thus, the new coordinates after rotation are \((8, -5)\).
So the correct answer is \((8, -5)\).