A car is initially at rest. The table gives the speedometer readings at intervals of $10\,\text{s}$. Which row describes the car’s motion in the first $30\,\text{s}$ and in the last $30\,\text{s}$?
- Anon-zero acceleration; at rest
- Bzero acceleration; constant speed
- Czero acceleration; at rest
- Dnon-zero acceleration; constant speed