What operation does a vapor recovery system perform in relation to pollution control?

A vapor recovery system plays a crucial role in preventing the release of harmful vapors into the atmosphere. This system captures volatile organic compounds (VOCs) that are released during various processes, such as the loading and unloading of liquids, primarily fuels. By trapping these vapors, the system reduces air pollution and mitigates the environmental impact associated with vapor emissions. This is particularly important in compliance with environmental regulations aimed at minimizing the release of harmful substances that contribute to air quality degradation and potential health risks.

While reducing air emissions from engines is important for pollution control, the specific function of a vapor recovery system is focused on capturing vapors rather than directly addressing emissions from engine combustion. Similarly, although enhancing water purification and improving fuel combustion efficiency are valuable operations within the broader context of pollution control, they do not correspond directly to the primary function of vapor recovery systems. Their main purpose is specifically to capture vapors to prevent atmospheric release, making option B the correct choice.