The diagram illustrates a food chain: rose bush $\rightarrow$ aphids $\rightarrow$ ladybirds $\rightarrow$ spiders. A disease caused the number of ladybirds to fall. What would be the most likely effect of this on the numbers of aphids and spiders?
- Aaphids decrease; spiders decrease
- Baphids decrease; spiders increase
- Caphids increase; spiders decrease
- Daphids increase; spiders increase