Fact 1: Plastics are made from petroleum and produce toxic waste. Fact 2: Toxic wastes can cause illness or death. Given the two facts above, what can cause illness?

OPTIONS: (1). a nylon cord (2). burning coal (3). a plastic bag (4). heat or cold (5). a wool sweater (6). a leather purse (7). Pesticides (8). Sulfur dioxide
The answer is:
(3).