This question cannot be answered properly without knowing at least the voltage of the light bulbs that are being asked about. When you know the bulbs' voltages then you will have to consider whether...
it takes 1 C type battery <><><> That answer is not really very helpful because the question doesn't say what the voltage of the light bulbs is! This question cannot be answered...
electrons become mobile due to potential formed by the battery. Now there are many ways in which light can be emitted, in basic bulb it is due to heating of filament .
It will depend on what battery you need. I use rechargeable AAA and AA batteries for my lights. Bike computer batteries will vary depending on the type used.