Final answer:
The drift velocities in different sections of a wire are inversely proportional to their cross-sectional areas. The current through a wire and its drift velocity also depends on Ohm's law, indicating an inverse proportion between current and resistance. Thus, the option "B" is the correct answer.
Step-by-step explanation:
The relationship between drift velocities in different sections of a wire carrying current 'i' after reaching a steady state is that they are inversely proportional to the cross-sectional area of the wire. Since the current 'I' is proportional to the product of the number of charge carriers (n), the charge of each carrier (q), the cross-sectional area (A), and the drift velocity (vd) as described by the equation I = nqAvd, a decrease in the area (for a wire with smaller radius 'r') will require an increase in drift velocity for the current to remain constant. This relationship dictates that for a given current, the larger the cross-sectional area of the wire, the lower the drift velocity, and vice versa.
As for Ohm's law, it states that current is inversely proportional to resistance, meaning that as resistance increases, current decreases, given a constant voltage. This can be understood through the formula I = V/R, where 'I' is current, 'V' is voltage, and 'R' is resistance.