A student performed an experiment to find out how temperature affects the volume of urine produced. Which row shows the experiment in which the environmental temperature was raised from $20^{\circ}\text{C}$ to $40^{\circ}\text{C}$, with no other changes made?
- Abefore: $60\ \text{cm}^3\ \text{per hour}$; after: $60\ \text{cm}^3\ \text{per hour}$
- Bbefore: $80\ \text{cm}^3\ \text{per hour}$; after: $40\ \text{cm}^3\ \text{per hour}$
- Cbefore: $120\ \text{cm}^3\ \text{per hour}$; after: $145\ \text{cm}^3\ \text{per hour}$
- Dbefore: $100\ \text{cm}^3\ \text{per hour}$; after: $130\ \text{cm}^3\ \text{per hour}$