In polluted industrial English cities during the Industrial Revolution, two plant diseases—black spot, which infects roses, and tar spot, which infects sycamore trees—disappeared.
Premise
In polluted industrial English cities during the Industrial Revolution, two plant diseases—black spot, which infects roses, and tar spot, which infects sycamore trees—disappeared.
Conclusion
It is likely that air pollution eradicated these diseases.
Evaluate
The argument mistakes correlation for causation. To strengthen this argument the correct answer should rule out an alternative cause, find another example where the cause is present and so is the effect, or find another example where the cause is absent and the effect is absent.