As of 2003, what percent of passenger vehicles offered head-protecting side airbags?

Answer: A — 40%

The correct percentage of passenger vehicles that offered head-protecting side airbags as of 2003 was indeed 40%. This reflects a significant advancement in vehicle safety features during that time. The introduction of head-protecting side airbags marked a key development in reducing injuries from side impacts, which are often more severe than frontal collisions. As automakers recognized the importance of side safety, many began to incorporate these airbags across a growing number of models, leading to a notable increase in their availability. Options that indicate lower percentages fail to capture the safety trends and regulatory measures that were pushing for improved occupant protection in vital areas of vehicle design during that period.