A copper wire connects the positive terminal of a 3 V battery to one side of a torch bulb. The other terminal of the bulb is joined to the negative terminal of the battery, completing the circuit. What is the direction of conventional current through the bulb filament?
(a) from the side connected to the battery’s negative terminal towards the side connected to the copper wire
(b) from the side connected to the copper wire towards the side connected to the battery’s negative terminal
(c) alternating back and forth inside the filament
(d) from the point of lower potential inside the filament to the point of higher potential