What car component can explode if exposed to heat after being filled with hydraulic fluid and compressed gas?

The correct answer focuses on the component that poses a risk of explosion when exposed to heat, particularly after being filled with hydraulic fluid and compressed gas. In the case of a bumper, modern vehicles often incorporate energy-absorbing systems that can include pressurized gas or hydraulic fluid for impact resistance or active safety features. If these components are subject to excessive heat, the pressure inside can build significantly, potentially leading to a violent failure or explosion.

While suspension springs, brake calipers, and fuel tanks also carry risks under certain conditions, they do not typically contain the combination of hydraulic fluid and compressed gas that would lead to an explosive situation when overheated. Therefore, the bumper is highlighted due to its specific construction and potential hazards associated with the materials used.