Final answer:
The cathode in a line notation battery is the negative terminal. The electrons flow from the negative terminal to the positive terminal.
Step-by-step explanation:
The cathode in a line notation battery is the negative terminal. In a battery, the electrons flow from the negative terminal to the positive terminal. The anode, on the other hand, is the positive terminal where electrons leave the battery. So, the correct answer is option b. Negative terminal.