B
Below is a question with multiple-choice answers. Choose the correct option based on your reasoning.

### Question:
An Italian scientist named Alessandro Volta invented the Voltaic pile in 1800. It was able to produce a steady electrical current. Based on this description, what is the modern equivalent of the Voltaic pile?

### Choices:
A. a wire
B. a battery
C. a resistor
D. a light bulb

### Answer:
