Small leaves duh and I know because I study it
Answer:
I believe it is B, direct contact
Explanation:
Ali most likely wasn't eating food that the dog had contaminated, nor was it likely that a mosquito first bit the dog and then Ali. This leaves A and D, and A seems to be more likely.
Apologies if I am incorrect.
The three major types of pollution are air pollution, water pollution, and land pollution. Sometimes, air pollution is visible. A person can see dark smoke pour from the exhaust pipes of large trucks or factories, for example. More often, however, air pollution is invisible.