What direction does current flow from a battery in a series circuit?

A. From negative to positive terminals

B. From positive to negative terminals

C. In alternating directions

D. In more than 1 direction

What's now called "Conventional current" is thought of as the flow of positive charge, from the battery's positive terminal to its negative one.

But it turns out that positive charges don't flow. The physical flow of charge is the flow of electrons. They come out of the battery's negative terminal, and carry negative charge around the circuit to the battery's positive one.