1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution Since resistance of the NTC falls we can say that the total resistance of the circuit has decreased so there is now more current in the circuit, so it's definitely answer B or D. And since X's resistance has fallen, PD across X will decrease too (because even though current has increased, the drop in resistance is bigger than the increase in current??) And since there is more current in the circuit, the pd of Y will increase??