A long, straight wire carries a current I as shown in the figure. Which of the following statements is true regarding the magnetic field due to the wire?
(a) The magnitude is proportional to I/r and the direction is out of the page at P.
(b) The magnitude is proportional to I/r2 and the direction is out of the page at P.
(c) The magnitude is proportional to I/r and the direction is into the page at P.
(d) The magnitude is proportional to I/r2 and the direction is into the page at P.
(e) The magnitude is proportional to I but does not depend on r.
