Answer:
[tex]\text{C.} \quad\dfrac{1}{2x}-10\ge 0[/tex]
Step-by-step explanation:
The contents of the radical must be non-negative. We cannot tell if the first term there is (1/2)x or 1/(2x). If the former, there is no correct answer choice. If the latter, the correct answer choice is ...
[tex]\dfrac{1}{2x}-10\ge 0[/tex]