A large open loop made of metal is constructed below a high voltage (AC) power line.

a) Can this loop be used to draw power from the lines? Where would the energy come from and how would it work?
b) If no one actually saw the loop, would the power company be able to detect the crime?
c)Could a similar approach be used to bug a telephone line? Explain your answer.

For a I said yes because an electric current creates a magnetic field around a conductor and because it's AC, the current alternates and so the changing magnetic field induces a current. I'm not sure where it's coming from, though or how it would work.
For b, I would say yes, but I'm not sure just how the phone company would know.
For c, I think it's also possible, but I'm not sure why, again.

please, I really ned help with this.