Which of the following statements is true regarding series and parallel circuits?

In a series circuit, all components are connected end-to-end, meaning the current that flows through the circuit passes through each resistor one after the other. When an additional resistor is added in series, it contributes to the total resistance by increasing the overall resistance of the circuit. This is because the total resistance in a series circuit is simply the sum of the individual resistances. Therefore, adding more resistors will only increase the total resistance, making statement C true.

In contrast, in a parallel circuit, multiple components are connected across the same two points, allowing multiple pathways for the current to flow. When a resistor is added in parallel, it creates another pathway for the current, effectively decreasing the total resistance. Thus, it becomes clear why removing a resistor in parallel actually increases the total resistance. Additionally, although voltage across parallel components is constant, it does not imply that parallel circuits use more voltage in general; rather, the voltage across each component remains equal to the supply voltage. Thus, this makes C the most accurate statement amongst those provided.