The Boltzmann distribution for a gas at constant temperature is illustrated below. If the gas temperature is lowered by $10\,^{\circ}\text{C}$, the shape of the graph alters. What happens to the values of $n$ at the points labelled $X$, $Y$ and $Z$?
- A$X$: higher; $Y$: lower; $Z$: higher
- B$X$: higher; $Y$: lower; $Z$: lower
- C$X$: lower; $Y$: higher; $Z$: lower
- D$X$: lower; $Y$: lower; $Z$: lower