31. During the heart's beating process, the activity of cardiomyocytes generates a magnetic field in space. In 1963, Baule and others first recorded the magnetic field generated by the electrical currents in the human heart, leading to the development of magnetocardiography (MCG). Using the Biot-Savart law to estimate the magnetic field. Suppose that I = A is the total current generated by myocardial activity and r = 0.1 m is the distance to the measurement point, what is the order of magnitude of the magnetic field generated by the heart in T? The permeability of free space is µ0=1.26× (T·m/A). (A)T (B) T (C) T (D)T (E) T