Final answer:
The correct answer to the riddle is 'nothing,' which illustrates the physical concept that nothing or a vacuum exists in the absence of matter and cannot coexist in the same space as matter.
Step-by-step explanation:
The question 'What's Nowhere but Everywhere, Except Where Something Is?' refers to the interesting concept of nothingness in a physical context. The correct answer is 'c) Nothing.' This riddle-like question alludes to the fact that 'nothing' or a vacuum can be found where there is an absence of matter or something, but it cannot exist in the same space as matter. In physical terms, no electric-field lines can exist at a point in space where there is nothing, meaning where there is no charge present to produce an electric field. Electric-field lines are a visual representation used in physics to depict the direction and strength of electric fields around charges. Hence, the statement that two electric-field lines cannot exist at the same point in space is correct because electric field lines do not cross, representing unique field directions at a point in space.