A business making bicycles has these costs at different output levels. Output $10$: total fixed costs $300$, total variable costs $800$. Output $20$: total fixed costs $300$, total variable costs $1500$. Output $30$: total fixed costs $300$, total variable costs $3300$. What happens to average total cost across this output range?
- AIt falls continuously.
- BIt falls then rises.
- CIt rises continuously.
- DIt rises then falls.