29. Coronal streamers in the Sun’s atmosphere contain magnetic fields in the opposite directions. The figure shows a model calculation of the magnetic field in a single streamer. The long dimension of the rectangular loop in the figure is400 Mm, and the magnetic field strength near the loop has a constant magnitude of 2 mT. What is the total current encircled by the rectangle? Note that the magnetic constant ?0 is 1.26 × 10⁻⁶ N/A² .

(A) 0 A
(B) 103 A
(C) 106 A
(D) 109 A
(E) 1012 A