Answer:
Car exhaust ultimately contributes to the problem of 2) climate change.
Step-by-step explanation:
The problem of climate change exists due to a number of factors contributing to it. The air pollution that the vehicles cause happens due to the fossil fuels burning like petrol and diesel.
Burning of these fuels leads to the emission of different oxides. These oxides act as a catalyst in the process of global warming ultimately contributing to climate change. These harmful gases lead to smog and many respiratory health issues. So, one has to use the public transport for short distance.