A Possible Explanation for the Fact That an Isolated Quark

Multiple Choice

A possible explanation for the fact that an isolated quark has yet to be found is that

A) the force between quarks varies inversely with their separation.
B) the potential energy of the quarks decreases with their separation.
C) the force between quarks is independent of their separation.
D) the force between quarks varies inversely with the square of their separation.
E) None of these is correct.