Transformers are used when electrical power is transmitted to houses. Which type of transformer is used at the power station before it is connected to the power lines, and which type is used before the supply is delivered to the houses?
- Apower station: step-down; before houses: step-down
- Bpower station: step-down; before houses: step-up
- Cpower station: step-up; before houses: step-down
- Dpower station: step-up; before houses: step-up