Which substance can aggravate paint problems when contacted?

All of the mentioned substances can indeed aggravate paint problems when they come into contact with automotive paint. Bird droppings contain uric acid, which can etch and damage the clear coat and paint finish if not removed promptly. Road salt can cause corrosion and lead to rust, particularly when it accumulates and retains moisture, thereby affecting the underlying metal and paint. Fuel spills can break down the paint and clear coat, leading to fading, blistering, or discoloration.

Since each of these substances has the potential to damage the paint in specific ways, selecting the option indicating that all of them can cause such problems is appropriate and accurate. Taking care to avoid these substances or addressing them immediately upon contact is crucial in maintaining the integrity of automotive finishes.