At a distance of 2.5 cm from a long straight current-carrying wire, the magnetic field has a value of 1.3 T. What would be the value of the magnetic field at a point that is twice as far from the wire, when the wire carries twice as much current?
a. 0.7 T
b. 1.3 T
c. 2.6 T
d. 5.2 T